ISSN 1172-6938

Issue 46 • April 2011

www.coastalsociety.org.nz

CONTENTS1 Planning Tools for Surf

Breaks

4 Coastal Impacts,Dynamics and Change:Insights from NorthCarolina to New Zealand

5 News from the Regions

8 Nearshore Currents andSediment TransportMechanisms in PocketBeach Environments

10 Profile: Denise Young

11 Marram Grass Seed Bankand Dispersal

13 NZCS ManagementCommittee and RegionalCoordinators

14 Monitoring OrganicEnrichment of CoastalSediment

15 Upcoming Conferences

16 Corporate Members

Te Hunga Takutai o Aotearoa

Preservation of coastal areas valued for surf ridingis gaining momentum through a variety of planningmechanisms. This has come about through themovement of surf communities, individuals andorganisations toward proactively preserving surfbreaks as finite, natural resources. This movementis, at least in part, in response to the many surfbreaks that have been degraded both overseas,and along our coastlines.

Surfing areas can be degraded in many ways,including impacts on their wave quality, access toa break, and their water quality. An internationalexample of a degraded surf break occurred in2005 when the World Championship Tour atMundaka, Spain was cancelled due to sub-standardwave quality during the event. The poor wavequality was the result of localised silt dredging.

Closer to home, surfers at Whangamata recentlysuffered ailments ranging from inflamed cuts tonausea to conjunctivitis after surfing Whangamatabar. This was the result of wastewater enteringthe surf zone after a heavy rainfall. Similar waterquality issues were apparent during theWhangamata Billabong Pro, a six-star event onthe Surfing New Zealand’s elite circuit.

An international movement

Since 2006, Australia has established 11 NationalSurfing Reserves. In July 2010, the US state ofHawaii passed laws to protect the famed breaksaround Waikiki and the North Shore on the islandof Oahu. In New Zealand, the Taranaki region hasrecognised 81 surf breaks in its Regional Policy

Planning Tools for Surf Breaksby Bailey Peryman and Matt Skellern

Statement. More recently, the New Zealand CoastalPolicy Statement (NZCPS) has afforded protectionto 17 of the country’s top surf areas (see Schedule1). Many other countries are preparing for thepreservation of surf breaks using similar techniques.

On top of these national and regional approaches,the World Surfing Reserves programme waslaunched in 2009 by the Californian-based Savethe Waves Coalition. With key partners, theInternational Surfing Association and NationalSurfing Reserves, the initiative aims to create a“UNESCO of surfing” to educate the world on thevalue of treasured surf sites and assist localcommunities with surf break protection1.

Malibu’s Surfrider Beach, California, USA, becamethe first dedicated World Surfing Reserve in October2010. Further World Surfing Reserves at ManlyBeach, Sydney, AU; Santa Cruz, California, USA;and Ericeira, Portugal have been confirmed.

Recently, New Zealand’s achievements with theNZCPS were commended by National SurfingReserves, Australia and World Surfing Reserves asbeing a world first in protecting surf breaks at thehighest level.

Surf breaks in the NZCPS

Surf-break protection policy came about due tothe significant response from surfers and surfing-related organisations to the review of the NZCPS1994. Around the time of the review New Zealandsurfers were questioning what effect the

Rocky Lefts, Paora Rd. One of the 81 surf

breaks identified in the Operative Taranaki

Regional Policy Statement. Photo courtesy

of Matt Skellern.

1 www.surfingreserves.org, retrieved 01/03/11.

The NZCS committee wish to

extend our thoughts and

sympathies to members and

friends affected by the events

in Canterbury. While many

affected members in

Canterbury will be part of

organisations that are able

to cater for their immediate

and future needs, the NZCS

would like to offer support

where it can through the

network of members around

NZ and the committee,

especially through the next

few weeks and months while

people try to get back to

normality. Please don’t

hesitate to contact any

members of the committee

if help is required.

CoastalNews

Coastal News No. 462

Northland Peaks – Shipwreck Bay; Peaks – Super tubes – Mukie 2 – Mukie 1

Waikato Manu Bay – Raglan; Whale Bay – Raglan; Indicators – Raglan

Taranaki Waiwhakaiho; Stent Road – Backdoor Stent – Farmhouse Stent

Gisborne Makorori Point – Centres; Wainui – Stock Route – Pines – Whales; The Island

Coromandel Whangamata Bar

Kaikoura Mangamaunu; Meatworks

Otago The Spit; Karitane; Murdering Bay; Papatowai

Whangamata marina proposal would have on theworld-class surf break located at the harbour’sebb-tidal delta. This proposal led to the formationof the Surfbreak Protection Society, whichsubsequently wrote the NZCPS an issues andoptions paper requesting that surf breaks beprovided for. The proposed NZCPS was released in2008 and included Policy 20 ‘Surf breaks of nationalsignificance’, which stated:

The surf breaks at Ahipara, Northland; Raglan,Waikato; Stent Road, Taranaki; White Rock,Wairarapa; Mangamaunu, Kaikoura; andPapatowai, Southland, which are of nationalsignificance for surfing, shall be protected frominappropriate use and development, includingby:

(a) ensuring that activities in the coastal marinearea do not adversely affect the surf breaks;and

(b) avoiding, remedying or mitigating adverseeffects of other activities on access to, anduse and enjoyment of the surf breaks2.

After the board of inquiry process, the NZCPS 2010

was gazetted on 3 December 2010, including Policy16 (replacing former policy 20), which states:

Protect the surf breaks of national significancefor surfing listed in Schedule 1, by:

(a) ensuring that activities in the coastalenvironment do not adversely affect thesurf breaks; and

(b) avoiding adverse effects of other activitieson access to, and use and enjoyment ofthe surf breaks3.

Key expert witnesses for the Surfbreak ProtectionSociety to the board of inquiry provided evidenceon oceanography, coastal science, planning andperspectives from the surfing industry. This leadingevidence should be referred to in developingresource management approaches towardsurf-break preservation.

Further to Policy 16, the NZCPS 2010 also containsa definition of surf break that describes a ‘surfablewave’ and ‘swell corridor’. Key changes tosurf-break policy through the board of inquiryprocess addressed the lack of justification for thenamed breaks in Policy 20, removed reference toremediation and mitigation of adverse effects (whichis not applicable to surf breaks), and mostimportantly replaced ‘coastal marine area’ with‘coastal environment’.

The landward component of the coastal environmentis essential for dealing with the maintenance ofwater quality and access to surf breaks. This is anarea where regional policy statements can provideguidance to district plans. Also catchment planningand coastal spatial planning can assist withmanaging landward aspects, as well as in thecoastal marine area. In evidence produced by theSurfbreak Protection Society, the seaward componentof the coastal environment was queried. This wasin regard to activities in the swell corridor beyondthe 12 nautical mile mark. There are potentialactivities in the swell corridor beyond this boundarythat could adversely affect surf breaks. For example,large-scale ocean energy generation, marine farmingor seabed mining. This raises questions on theability of the RMA to address these issues, andthe need for ocean policy.

The Whangamata bar over Anniversary weekend

2011. This day the bar was known as the ‘Chocolate

Bar’. Photo courtesy of COL/SURF2SURF.com.

Schedule 1 – Surf Breaks of National Significance

2 Department of Conservation, 2008. Proposed New Zealand

Coastal Policy Statement 2008. Retrieved 21/10/10 fromwww.doc.govt.nz/upload/documents/getting-involved/consultations/current-consultations/proposed-nzcps-2008-high-res.pdf.

3 Department of Conservation, 2010. New Zealand Coastal

Policy Statement 2010. Retrieved November 21, 2010 fromwww.doc.govt.nz/upload/documents/conservation/marine-and-coastal/coastal-management/nz-coastal-policy-statement-2010.pdf.

CoastalNews

April 2011 3

Protecting a diversity of surf breaks

The board of inquiry in its findings made thefollowing statement:

“We conclude that there should be no criteriain the policy [NZCPS 2010] for selecting furthersurf breaks of national significance given thatthere could be developments in the methodologyin identifying and rating natural surf breaks.For example, we note the strong plea by manysubmitters for ensuring diversity of surf breaksso that all surfing skill levels are provided for4.”

This plea was accommodated by the Minister ofConservation by including surf breaks as part ofthe natural character of the coastal environmentin Policy 13 of the NZCPS. Policy 15 is also relevantas surf breaks are natural features within theseascape. Councils are now tasked with consideringhow they will give effect to mapping and identifyingnatural character and natural features in regionalpolicy statements and plans.

A regional perspective

At the regional level, work has been conducted onthe methodology of identifying and rating naturalsurf breaks. This includes the formal process Taranakiwent through to identify surf breaks. Also, theformer Auckland Regional Council carried out workon the methodology for assessing surf breaks,although this has not resulted in any public policyto date.

During summer 2010-2011, the Bay of Plenty RegionalCouncil and Gisborne District Council engagedBailey as a summer student to complete a studyon surf breaks for each region. While these studiesbuild on existing approaches to surf-breakidentification and methodology for assessment,Bailey’s work focused on engaging the public onsurf-break preservation. A variety of local participantsfrom the surfing community, surf industry, economicdevelopment, surf lifesaving, territorial authoritiesand tangata whenua were asked to provide input.This was via workshops, a series of interviews andother communications.

There are a number of variations between thestudies as a result of different statutory demandsin each of the study areas. The outcomes of theGisborne District Council study are pending at thetime of writing.

The Bay of Plenty Regional Council study identifiesand describes regionally significant surf breaks. Itthen attributes a set of outstanding characteristicsand values to each break, through a set ofassessment criteria that were developed inconsultation with the public. The study reveals thatthe community is strongly in favour of continuinga proactive approach to protecting surf breaks asregionally and locally significant natural resources.

It also identified that surf breaks are important formany types of recreation. This can include theenjoyment from the passive onlooker, surfing, surflifesavers, body surfing, kite surfing, paddle boardingand all other forms of surf riding.

The Bay of Plenty Regional Council study hasdemonstrated that surfing is a lifestyle for many,and is strongly embedded in the social fabric ofmany coastal communities. The study confirms thatwithin the region surfing provides an economicbenefit and generates tourism. Surf breaks werealso identified as significant for cultural heritage,including the connection for Maori. It is understoodthat early Maori practised the art of wave ridingout of necessity and for leisure. The Bay of PlentyRegional Council study further demonstrates thatthe values of surfing span the four well-beings –social, economic, cultural and environmental.

For planning and giving effect to the NZCPS 2010,early indications from both studies suggest acollaborative approach is most effective for policydevelopment at the regional and district councillevels. Both studies provide valuable insights forplanners and others in applying this new area ofresource management policy.

Bailey Peryman is a fourth-year Environmental

Management student at Lincoln University interested

in the development of surf-break policy provisions

within the New Zealand resource management

framework.

Matt Skellern is completing his Masters in Planning

at the University of Auckland. He is carrying out a

research thesis on international approaches to

surf-break protection.

The Banzai Pipeline, on Hawaii’s North Shore, during

2009 Pipe Masters. Senator Fred Hemmings made

this wave part of the Hawaiian Surfing Reserves,

he also ran the first Pipe Masters event in 1971.

Photo courtesy of Matt Skellern.

4 Department of Conservation, 2009. Proposed New Zealand

Coastal Policy Statement 2008: Board of Inquiry Report

and Recommendations. Retrieved October 21, 2010 fromwww.doc.govt.nz/upload/documents/getting-involved/consultations/closed-consultations/nzcps.

CoastalNews

Coastal News No. 464

On 20 December 2010 about 30 people attendedan NZCS seminar featuring JP Walsh. The seminarwas hosted by Canterbury regional coordinatorJustin Cope, with lunch provided by EnvironmentCanterbury. Dr Walsh delivered a dynamic andinteresting overview of the geomorphic behaviourand management issues of river coasts from easternNorth Carolina to the Mississippi Delta and Gulfof Mexico, and New Zealand’s Waipaoa catchment.His research uncovers how materials from land aredispersed and accumulate in the ocean, includingin estuaries. From November 2010 to January 2011,Walsh was serving as a visiting scientist at NIWAin Wellington, enabling him to visit Christchurchand speak.

Walsh is associated with several ‘source to sink’coastal projects where he uses sedimentcharacteristics, in combination with multiple typesof high-tech geophysical and imaging methods, tounderstand the modern and ancient processesinfluencing the sedimentary records of continentalmargins. The results quantify rates of sedimentationand seabed reworking, highlight the fate ofpollutants and runoff, quantify coastal hazard risksand natural resources such as land- and beach-nourishing sand, indicate the ecological ramificationsof coastal erosion, and help to inform coastalmanagers and residents about the dynamics oftheir coastlines.

North Carolina, Walsh’s home state, has about amillion coastal plain residents and 16 000 km ofestuarine and barrier island shore. This includes thesecond largest estuary in the United States, theAlbemarle-Pamlico system, which is enclosed bysandy barrier islands formed during the Holoceneand reworked by modern storm processes. Most ofthe coast is low-lying, with much of the estuarineshores characterised by salt-marsh habitat.

Accelerating sea-level rise, seasonal hurricanes andstorms, and variable barrier sand volumes produceinundation, and episodic and chronic erosion. Insome areas storm and hurricane events also re-worklarge volumes of estuarine bed sediments, meaningthat historical pollutants buried in the sedimentsare continuously recycled through the ecosystem.

Across several North Carolina counties, an averageof 7% of the estuarine shore has been hardenedin response to erosion, but the ocean shorelineremains almost entirely devoid of structures becauseof strict state development regulations.

Barrier island roll-back through overwash andintermittent inlet openings occur regularly alongthe developed and undeveloped areas of the OuterBanks. Federal insurance limits compensation on

Coastal Impacts, Dynamics and Change:Insights from North Carolina to New Zealand

NZCS seminar by JP Walsh, Institute for Coastal Science and Policy, East CarolinaUniversity and NIWA Visiting Scientist. Reviewed by DE Hart.

JP Walsh during an instrument repair effort in

Albemarle Sound, North Carolina.

properties damaged during such events to one-offclaims up to US$250,000. Residents who wish tomaintain properties in vulnerable areas mustshoulder the financial costs of repeat disasterswith limited redevelopment and private insuranceoptions. In the absence of tighter planning controls,this post-Hurricane Katrina reality has ironically ledto an increasing number of locally funded beach-nourishment projects, as well as requests for hard-engineering projects as communities fight to maintainhazard-prone coastal developments.

Walsh described a series of detailed mappingprojects that have led to the production of public-access, user-friendly tools to quantify coastalhazards. These tools have been brought togetherin the form of the North Carolina Coastal HazardsDecision Portal or NC COHAZ website (see:http://coastal.geology.ecu.edu/NCCOHAZ/maps.html).

In New Zealand, Walsh is involved with the Marginsproject case study of the Waipaoa River delta. Withsupport from the US National Science Foundationand in collaboration with Dr Alan Orpin at NIWA,Walsh’s team is investigating the possibility ofdetecting individual catchment and ocean eventsin the sediments deposited offshore of the WaipaoaRiver system near Gisborne.

To foster more collaboration betweensedimentologists and oceanographers, Walsh andOrpin are organising a meeting to be held in NewZealand (likely in 2011) that will bring togetherNew Zealand and international scientists to discussmeasurement and modelling methods and insights.

If you wish to help coordinate and/or participatein this meeting, please contact Walsh atwalshj@ecu.edu. He is also happy to be contactedwith questions about his research activities.

CoastalNews

April 2011 5

Northland Regional NewsMichael Day, Northland Member

Consents

Kaipara Harbour Tidal Turbines

Crest Energy Limited has been given the go aheadby the Environment Court to place up to 200 tidalturbines on the seafloor at the entrance of KaiparaHarbour. At time of writing, the proposal wasawaiting the approval of the Minister of Conservationfor the Restricted Coastal Activity elements of theproposal – the final step in the resource consentprocess.  A number of consent conditions areattached to the resource consents includingmonitoring and review of environmental effects.Turbine installation will progress in stages, eachstage being reviewed by the consent authoritybefore being allowed to proceed to the next stage.

Paihia Waterfront Redevelopment

The proposed Paihia Waterfront Redevelopment isnow moving into the construction phase followinga favourable decision from the Environment Court.There are both commercial and public elements tothe proposal, the main components are:

• an extension to a previous reclamation toprovide improved public coastal access andimproved and additional berthing facilities forcraft;

• sites for three maritime related buildings, alongwith landscaped open space, seating and otherpublic facilities;

• a wave attenuator, as well as a number of otherstructures to improve the overall facilities atPaihia; and

• a relocation of the navigation channel to thePaihia Wharf.  

A key public feature of the proposal is therenourishment of Horotutu Beach, which is adjacentto the Paihia township centre. The renourishedbeach is to be protected by two reef-typebreakwaters.  These breakwaters were among theissues in contention throughout the resourceconsenting process.  

Policy Development

The regional council has given effect to Policy 29of the New Zealand Coastal Policy Statement 2010by removing all references to restricted coastalactivities from the Northland Regional CoastalPlan.

The development of a new Northland RegionalPolicy Statement is progressing. The regional councilproduced a discussion document which was releasedfor public comment in October last year. Thisdiscussion document generated a high level ofinterest with 158 submissions received. Staff haveprepared a summary of feedback and are currentlyworking on developing a draft Regional Policy

News from the Regions

Baylys Beach Bonanza, Waitangi Day 2011.

Credit: Laura Shaft, Coast Care Coordinator,

Northland Regional Council.

Statement (which is expected to be released forpublic comment by August 2011).

A link to this work can be foundhere:  www.nrc.govt.nz/Your-Council/Council-Projects/New-Regional-Policy-Statement-/Project-overview.

Coastal Updates

Vehicles on Beaches

This has been the fifth summer for the NorthlandSafe Beach Driving Education Programme, coordinatedby Northland Regional Council and supported bythe Police, the Department of Conservation, thedistrict councils and the NZ Transport Agency. Multi-agency patrols were organised for key Northlandbeaches including Bream Bay and Ninety MileBeach. Other events were attended by agency staffto promote safe beach driving messages. Newsignage has been developed and erected on theroads to beaches where vehicles are driven. Thesesigns each contain one key message for less harmfulbeach driving, such as “keep off the dunes”.

Mangrove Management

The Mangrove Management Support Programme(MMSP) was launched in September 2010 with acall for expressions of interest from communitygroups. Having reviewed all of the expressions ofinterest, the regional council resolved at its January2011 public meeting to support 10 proposals throughthe programme. In determining which proposals toprogress, consideration was given to a range ofcriteria including; the consistency of each proposalwith the relevant Regional Coastal Plan provisions;the group’s ability to complete the associatedphysical works; the ecological values of the areasaffected; and the level of wider community supportfor each proposal.

To date, MMSP has assisted with the processingcosts for two limited-notified consent applicationsoccurring in the Mangawhai and Kaipara harboursand consent has now been granted for these relativelysmall-scale projects. Work commenced in Februaryfor a further seven of the selected proposals with

CoastalNews

Coastal News No. 466

Mangrove Management work being done in

Mangawhai Harbour.  The Mangrove Management

Support Programme is helping to fund this work.

Credit: Ricky Eyre, Coastal Monitoring Officer at

Northland Regional Council.

a view to submitting resource consent applicationsin June 2011. Northland Regional Council appointedBeca to assist with this work, principally thepreparation of the resource consent applicationsand supporting environmental effects assessments.The latest step in the process has been the onsitemeetings between the council, Beca and thecommunity representatives to discuss and refinethe mangrove management boundaries to ensurethat realistic and achievable proposals are progressedto consent lodgement.

Those community groups with successful consentapplications will be legally and financially responsiblefor undertaking the associated works and any long-term management requirements. The council hopesthat the MMSP programme will be a catalyst forfurther estuary and catchment managementinitiatives in the areas of concern.

Monitoring and Science

Dredging and beach renourishment in the outerMangawhai and Whangarei harbours were monitoredin February. Sand used in the Mangawhai intertidalarea was good quality and well graded. Unfortunatelythe sand at Marsden Cove was not adequate forbeach renourishment and needed to be removed.

Sedimentation rates were measured at several sitesin Kerikeri Inlet, Ruakaka, Whangarei Harbour andthe Kaipara Harbour. This was undertaken toinvestigate the effects of cyclone Wilma on sedimentdeposition in estuaries.

Auckland Regional News

Waterview Connection Project

Alastair Senior, Regional Coordinator

The Waterview Connection Project is the last linkin the Western Ring Route around Auckland and isthe largest roading project in New Zealand. This‘Road of National Significance’ joins SH20 to SH16and includes major upgrades to the SH16 Causeway.These upgrades include widening the causewayand lifting the final road level to account for sea-level rise predictions.

Consent applications for this project were submitted

to the Environmental Protection Authority (EPA) inSeptember 2010. The EPA Board of Enquiry iscurrently at the hearings stage within theEnvironment Court.

The New Auckland Council

Kath Coombes, Auckland Region and Membership

Coordinator

The city, district and regional councils in Aucklandwere amalgamated to form the new AucklandCouncil on 1 November 2011. As a unitary authority,the council has coastal responsibilities for the landand coastal marine area.

One of the priorities for the council is to preparethe Auckland Spatial Plan, a requirement of thelegislation that established the council. The spatialplan will guide the future growth and developmentof the Auckland region over the next 20 to 30years. Specifically, it will deal with: key infrastructureneeds; the future location and mix of residential,business and industrial activities in specific areas;significant recreational, open space and ecologicalareas; the social, economic, environmental andcultural well-being of the region; and protectionand enhancement of the built and naturalenvironment. Many of these elements will haveimplications for the region’s coastal areas. It isexpected that the plan will be completed by theend of 2011. A discussion document will be releasedfor public comment over March and April 2011.

The council is also working on a unitary plan toreplace the current regional and district plans. Theunitary plan will be one of the ways the spatial planis implemented. This work is currently in an earlyscoping phase and it is yet to be determined whetherall or some of the regional coastal plan will beincorporated into the unitary plan. It is hoped thata draft unitary plan will be prepared by late 2012.

A new feature of the Auckland Council is the creationof 21 local boards with 149 elected members. Theboards were established to enable local representationand decision-making on behalf of local communities.They have responsibility for budgets totalling $488million (for 2011 – 2012) and manage the fundingof a wide range of community services, facilitiesand activities in their local area. The boards arecurrently working on their local board plans to setout their aspirations and priorities for the next threeyears. Numerous coastal projects have been identifiedfor possible inclusion, including foreshore andestuarine enhancements, beach re-sanding, erosionworks, walkways, ecological restoration and mangrovemanagement.

Development of the Auckland city CBD waterfrontis now the responsibility of Waterfront Auckland,an Auckland Council organisation. The agency is alandowner or leaseholder for significant areas ofland but also leads the development and deliveryof the waterfront master plan for the wider waterfrontarea. The agency applies to the council for resourceconsents and plan changes. Physical works arecurrently underway in transforming the North Wharfand Gateway Plaza area of Wynyard Quarter into

CoastalNews

April 2011 7

Ministerial Advisory Panel on a site visit to the

proposed Coromandel marine farming zone.

Photos courtesy Ministerial Advisory Panel Member.

a public space. The waterfront agency’s website atwww.waterfrontauckland.co.nz has details on whenthe different stages of development are planned.

Many council staff have changed roles and/orlocation with the new council. The various teamswith coastal responsibilities are spread around theregion: policy and planning, research and monitoringare in Takapuna; resource consents are in theAuckland CBD; and environmental services are inMt Roskill and Orewa. Council officers are workingon mechanisms to ensure coastal management isintegrated across the council.

Further information about the Auckland Council isavailable at www.aucklandcouncil.govt.nz.

Waikato Regional News

Aquaculture in Waikato

Graeme Silver, Waikato Member

There are big changes afoot for aquaculture andnowhere is this truer than in Waikato.

While the proposed removal of the requirement formarine farming to occur within an aquaculturemanagement area will have little effect due to abroad prohibition on aquaculture in the WaikatoRegional Coastal Plan, the Aquaculture LegislationAmendment Bill (No 3) (the Bill) proposes to directlyamend the plan.

A ‘deemed’ plan change inserted by the Bill willallow consent applications for fish farming withinthe Wilsons Bay Zone and other existing farms,and will allow small extensions (about 1 to 2 ha)to the pre-RMA farms outside the zone. Fish farmingin the Wilsons Bay Zone will be limited to about4000 tonnes per year based on a nutrient dischargecap of 300 tonnes per year.

In a parallel process, the Minister of Aquacultureappointed a Ministerial Advisory Panel to hearsubmissions on a proposal to create a new marinefarming zone near Coromandel Harbour. This 300-ha zone would be primarily intended for fish farmingand could cater for about 8000 tonnes of annualproduction. The panel, consisting of Sir Doug Kidd,Mark Farnsworth and Justine Inns, heard submittersduring the second week of February and is expectedto report back to the Minister in early March.

There are several options if the zone proceedsincluding insertion into the Waikato Regional CoastalPlan by the Bill, through the new regulation-makingpowers that the Bill proposes to grant the Minister,or a normal RMA plan change process.

Once the new laws are in place and transitionalmatters are dealt with, Environment Waikato willbe preparing a regional Aquaculture DevelopmentStrategy in partnership with stakeholders.

This strategy will identify the opportunities forsustainable growth of marine farming, theinfrastructure required to support it, and identifyspecific areas from which aquaculture should beexcluded. The strategy will then inform the upcomingreview of the regional coastal plan and the excludedareas will be included as part of a broad zoningapproach to our second generation coastal plan.

CoastalNews

Coastal News No. 468

Sediment transport, one of the most commonsubjects in coastal engineering, is the process ofthe movement of sands in bedload and suspendedforms. Although this movement occurs underdifferent wave, wind and tidal conditions, theplanform topography of the coast plays a majorrole in determining the circulation system andconsequently sediment transport mechanisms.

Beaches can be divided into three types based ontheir planform morphology and degree of exchangeswith adjacent coastlines: open, embayed, and pocketbeaches (Short, 1999). About 80% of coastal areasworldwide are formed along the fringes of mountainsand exposed rocks, resulting in an abundance ofthe sheltered beach types: embayed and pocketbeaches (Ojeda and Guillen, 2008). Despite suchubiquity, our knowledge of the nearshore currentsand sediment transport mechanisms operating inthese specific environments, especially in pocketbeaches, is very poor compared to our understandingof these processes on open coast beaches (Dehoucket al., 2009).

Over the last few decades much literature hasfocused on the stability of sheltered beach shorelines(Dehouck et al., 2009; Klein et at., 2002b), butfew studies have quantified the nearshore processesinfluencing this stability (Ojeda and Guillen, 2008).Further, artificial pocket beaches are a commonfeature of built coastal environments, such as portcities. The creation of pocket beach morphologieshas been recommended as a solution to erosionproblems for some coastal areas (Ojeda and Guillen,2008).

Sediment transport mechanisms in sheltered coastalareas are significantly affected by the length ofboth headlands and of the shoreline, and also bythe distance between two headlands. In order toclassify a sheltered beach and to define its dominantnearshore circulation system, a dimensionlessembayment scaling parameter can be applied ( ′δ )(Short 1999, 2010):

′δ = S12 / 100C1 Hb( )

where S1 is the length of the embayment shoreline(m); when the end points of S1 are located at theouter ends of the surf zone, not the outer ends ofthe embayment. C1 is the distance between twoheadlands (m) and Hb is the breaking wave height(m).

If ′δ >19, the area is classified as an open coast andhas normal beach circulation. If 8< ′δ <19, the areais classified as an embayed beach and hastransitional circulation (for example, crenulated bay

Nearshore Currents and SedimentTransport Mechanisms in Pocket

Beach EnvironmentsArash E. Moghaddam and Deirdre E. Hart,

Department of Geography, University of Canterbury, Christchurch 8140, New Zealand

Figure 1: A crenulated bay located in the south

east of the North Island, Castlepoint, New Zealand,

(LINZ, 1998).

is a subcategory of embayed beaches that arecharacterised by a long spiral planform shape,including an area sheltered from waves) (Figure 1).If ′δ <8, the area is classified as a pocket beach(Prof A. Short, Coastal Scientist, University of Sydney,pers. comm., 09/05/2010) and is dominated bycellular circulation, with longshore currents limitedinside the bay and megarip currents formed nearheadlands (Figure 2).

Observations indicate that pocket beaches are moresensitive to changes in the direction and magnitudeof sediment transport, and that wind and tidescould have potentially greater influence on theseprocesses than on open beaches with similaroffshore wave conditions (Dehouck et al., 2009).The net sediment transport in pocket beaches islimited by their longshore boundaries.

Along with catchment influences, this limited nettransport affects the stability of the shoreline overannual time scales. The shoreline profile, however,is more sensitive over short-term periods (monthly)and changes quickly, with longshore rotationprocesses and cross-shore berm/bar profile changescommonly occurring. The occurrence of longshorerotations depends on longshore currents, whichare controlled by the length and distance betweenheadlands in pocket beaches.

Despite some studies conducted on sedimenttransport mechanisms and mostly on shorelineconfigurations in pocket beaches, more studies areneeded in order to improve our knowledge of

CoastalNews

April 2011 9

Figure 2: Examples of pocket beaches enclosed by rocky headlands on Banks Peninsula, Canterbury, New

Zealand – 2a, Okains Bay; 2b, Lavericks Bay.

nearshore currents and, consequently, sedimenttransport mechanisms under differing wave, tideand wind regimes for pocket beach environments.

These studies should involve:

1) the behaviour of nearshore currents at differentlevels within the water column;

2) a proper evaluation of the influence of windsand tides on onshore and cross-shore currentsinside pocket beaches and of longshore currentson sediment exchanges between pocket beachesand adjacent coastal areas;

3) examining the major mode of sediment transport(suspended load/bed-load); and

4) examining the role of periodic high-wave events,especially storms, and ensuing recovery periods.

As the part of a PhD project, we are planning tomeasure waves, winds, tides, currents and sedimenttransport inside the pocket beach of Okains Bayfor one year. This field data will then be used todevelop 2D Xbeach model simulations of processesand shoreline morphodynamics inside the bay. Thismodel has been developed for hurricane and stormconditions. Figure 3 shows an initial example ofthe simulation of currents and suspended sedimenttransport with a theoretical 1.5 m swell wave heightapproaching the shoreline of Okains Bay at 45˚.

As can be seen in Figure 3a, headlands shelter thebay from incoming waves, so that waves enter tothe bay after diffraction and refraction, therebydecreasing the wave heights.

Figure 3b indicates that the swell wave-generatedcross-shore currents are stronger close to theheadlands compared to other areas. Currents veryclose to the headlands flow in the offshore direction,while those in the central majority of the bay movetowards the shoreline direction on this incomingtide. The bed return flow is also shown in Figure3c.

This type of current dominates areas close to theshoreline and headlands and it becomes more

significant at the end of headlands exposed to theswell waves.

The cross-shore suspended sediment transportinside the bay appears to be limited as a result,which is consistent with most pocket beach literature(Figure 3d). This process, however, increases closeto the headlands where the cross-shore currentsare stronger. Sediment tends to be exchanged withadjacent coasts as headland sand bypassing.Generally, it seems that there is a good agreementbetween the results of this model at Okains Bayand pocket beach literature, but the model has notyet been validated using field data. The next stageof this project involves validating the Xbeach modelfor Okains and Lavericks bays, and exploring theadjustments in physical parameters needed tomodify the model for use in pocket beachenvironments.

References

Dehouck, A, Dupuis, H and Sénéchal, N, 2009.“Pocket beaches hydrodynamics: The example offour macrotidal beaches, Brittany, France”, Marine

Geology 266, pp. 1-17.

Klein, A H F, Benedet, L and Schumacher, D H, 2002.“Short-term beach rotation processes in distinctheadland bay beach system”, Journal of Coastal

Research 18, pp. 442-458.

LINZ, Land Information New Zealand, 1998. New

Zealand Map Grid Non Geo-referenced Orthophoto

V23 – Waipukurau. Retrieved 16 January 2010 from:http://www.linz.govt.nz/topography/aerial-images/nzmg-non-geo/apv23/index.aspx.

Ojeda, E and Guillen, J, 2008. “Shoreline dynamicsand beach rotation of artificial embayed beaches”,Marine Geology 253, pp. 51-62.

Short, A D, 1999. Handbook of Beach and Shoreface

Morphodynamics, Chichester: Wiley, New York, pp.230-249.

Short, A D, 2010. “Role of geological inheritance inAustralian beach morphodynamics”, Coastal

Engineering 57, pp. 92-97.

CoastalNews

Coastal News No. 4610

We welcome Denise Young toour Management Committee.Denise will be the committee’sCentral Government Liaison.

Denise is a Senior Planner inthe Policy Group at theDepartment of Conservation’s

(DOC) national office in Wellington. She hasworked for DOC since 2001.

Apart from a secondment to prepare the Mount

Profile: Denise YoungAspiring National Park Management Plan, Denisehas worked almost exclusively on coastal issues,including helping Dr Jo Rosier undertake theindependent review of the New Zealand CoastalPolicy Statement, the aquaculture review, andthe review of the Foreshore and Seabed Act.

Prior to working for DOC, Denise worked for TePuni Kokiri, the Otago Regional Council and theNew Plymouth District Council. She has a Mastersin Resource and Environmental Planning fromMassey University.

Figure 3: Modelled wave height (a) cross-shore mean velocity; (b) red colour indicates onshore, blue

colour indicates offshore, bed return flow; (c) cross-shore suspended sediment transport; (d) red

colour indicates onshore, blue colour indicates offshore in Okains Bay generated using a one-hour

incoming-tide simulation of Xbeach.

NZCS Mission StatementThe New Zealand Coastal Society was inaugurated in 1992 “to promote and advance sustainable

management of the coastal environment”.

The Society provides a forum for those with a genuine interest in the coastal zone to communicateamongst themselves and with the public. The Society currently has over 300 members, including

representatives from a wide range of coastal science, engineering and planning disciplines, employedin the engineering industry, local, regional and central government, research centres and universities.

Applications for membership should be sent to NZCS AdministratorHannah Hopkins (email: nzcoastalsociety@xtra.co.nz).

Opinions expressed in Coastal News do not necessarily represent those of the editor, the management committeeor the New Zealand Coastal Society. Every effort is made to provide accurate and factual content. The publishersand editorial staff, however, cannot accept responsibility for any inadvertent errors or omissions that may occur.

CoastalNews

April 2011 11

Although marram grass has some utility in coastal

protection, its spread into New Zealand’s relatively

pristine dune systems has been ecologically

catastrophic. The focus of this study has been to

investigate the nature of the marram grass seed

bank and the dispersal of seed in the dune systems

of southern New Zealand.

Marram grass seed ecology

For this study, marram grass seed ecology wasinvestigated using a variety of techniques includinggermination and greenhouse experiments, viabilitytesting of seed, seed bank sampling and fieldobservations. We took advantage of situations wherethe age of strata was known to age individual seeds.The ability of seed to germinate at different burialdepths and light conditions was tested in order toimitate natural conditions.

Marram grass seed is highly sensitive to light duringgermination, and only emerges from burial at veryshallow burial depths of between 0 and 5 cm. Thissuggests that marram grass seed is well adaptedto the continuous movement of sand, where burialdepths can change over a short period of time. Arelatively fast germination response to a shallowerburial depth is important for marram grass seed,to avoid desiccation of the seed as a result ofexposure by wind erosion and to quickly establishat a new site.

Temporal separation

Ageing the seed bank was deemed to be the mostchallenging aspect of this study and two novelmethods of temporal separation were used. First,a set of aerial photographs of Allans Beach, OtagoPeninsula, taken between 1982 and 2009, wereused to trace the formation of four parallel duneridges over time. Seed gathered from each of thesedune ridges was therefore assumed to be of aspecific age corresponding to the age of each duneridge.

The possession of a set of dune profiles collectedover the course of 21 years at St Kilda Beach,Dunedin, provided the second opportunity fortemporal separation. From these dune profiles (Figure2) it was expected that seed collected from specificdepths would correlate to the date of each dune

Marram grass (Ammophila arenaria) has come todominate the coastal dune systems of the lowerNorth Island and most of the South Island. Thishas occurred through a combination of natural,long-distance, dispersal and human-facilitatedspread (Figure 1).

Marram Grass Seed Bank and DispersalBy Daniel Lim, Department of Geography, University of Otago, Dunedin

Supervisors: Dr Mike Hilton, Department of Geography, University of Otago, Dunedin andDr Janice Lord, Department of Botany, University of Otago, Dunedin

Figure 1: A map highlighting the extent of Ammophila

arenaria distribution along the coastal dune

environments and the distribution of nationally

and internationally significant dune systems.

Figure 2: The 21-year dune profile record of St Kilda Beach, Dunedin, used to approximate seed bank ages.

Points 1 and 2 indicate coring positions.

CoastalNews

Coastal News No. 4612

profile. This provided relatively robust temporalseparation for ageing the seed bank. This approachproved to be a faster method of investigating seedbank nature compared to other methods.

Establishment of seedlings

Previous studies of marram grass seed suggestthat the establishment success of seedlings isextremely limited, with the majority of establishedseedlings being found in moist, sheltered micro-sites such as a dune slack in the lee of a dune.Even in these micro-sites, however, the rate of theestablishment of marram grass seedlings has beenfound to be extremely low (Huiskes, 1977; Laing,1956). Low establishment rates would suggest alow risk of marram grass seed invasion in the duneenvironments of southern New Zealand.

Our field study at Stewart Island’s Doughboy andMason bays, however, contradicts these earlierfindings and suggests that marram grass seedpresents a real invasion and re-invasion threat todune systems.

Field study at the foredune at Doughboy Bayshowed seedling emergence for at least sevenyears after initial spraying. This seed bank had notpreviously been anticipated.

At Mason Bay, seedling surveys conducted in thecentral dune system showed the emergence of alarge number of marram grass seedlings suggestingsuccessful invasion of marram grass seed. At MasonBay, seedlings also showed a greater tendency toemerge outside of moist, sheltered micro-sites.

Dune systems at risk

The findings of this study have shown that seedplays a key role in the invasion of marram grassinto dune systems in southern New Zealand. Thisis especially true for the larger west coast dunesystems, where the predominantly westerly windprovides ideal conditions for the dispersal of seed.The natural conditions within the marram grassforedune in southern New Zealand also appear to

support the development of a viable seed bank,which provides a source for re-invasion.

The investigation into seed bank age showed thatmarram grass seed remains viable up to andpotentially beyond 21 years of age. This findinghas implications for the duration of marram grasscontrol programmes in specific dune systems,although other processes (increased sedimentation,for example) may shorten the effective life of theseed bank. Once a mature population of marramgrass has been sprayed and dies off, monitoringand follow-up spraying will likely be required foran extended period of time. This period of timemay be greater than the 10 years suggestedpreviously. This is likely to be particularly the casein foredune environments where rapid accretionand progradation may assist seed accumulationand storage.

The final product of this study included a conceptualmodel of marram grass invasion at Mason Bay. Ourfindings suggest that control operations on Stewart

Figure 3: Dr Mike Hilton collecting a four-metre

core at St Kilda Beach, Dunedin.

Figure 5: Conducting field work on the marram

grass foredune.

Figure 4: Pingao (Ficinia spiralis) colonised dunes

at Mason Bay, Stewart Island.

CoastalNews

April 2011 13

Island will need to plan for a prolonged monitoringprogramme, with special attention on the foredunewhere the greatest threat of re-invasion exists.

In larger dune systems, systematic seedling surveysshould also be carried out every two to five yearsin order to prevent the establishment of any newpopulations of marram grass.

ReferencesHuiskes, A H L, 1977. “The natural establishment

of Ammophila arenaria from seed”, Oikos, 29(1),pp. 133-136.

Huiskes, A H L, 1979. “Biological flora of the BritishIsles: Ammophila arenaria”, Journal of Ecology, 67,pp. 363-382.

Laing, C C, 1958. “Studies in the ecology ofAmmophila brevigulata 1. Seedling survival and itsrelation to population increase and dispersal”,Botanical Gazette, 119, pp. 208-216.

Contributing to Coastal NewsCoastal News welcomes contributions for each issue. Please contact Shelly Biswell at shelly@biswell.net

if you’d like to submit a news brief or article.

The submission deadline for the next issue of Coastal News is 1 June 2011.

For any enquiries regarding Coastal News articles, please contactNZCS Editor Shelly Biswell (shelly@biswell.net).

NZCS Management CommitteeChairperson: Deirdre Hart deirdre.hart@canterbury.ac.nz

Deputy Chairperson: Rick Liefting rliefting@tonkin.co.nz

Treasurer: Eric Verstappen eric.verstappen@tdc.govt.nz

Membership Coordinator: Kath Coombes kath.coombes@aucklandcouncil.govt.nz

Regional Coordinator: Hugh Leersnyder hugh.leersnyder@beca.com

Student Coordinator: Karin Bryan k.bryan@waikato.ac.nz

Coastal News Coordinator: Cushla Loomb cushla.loomb@beca.com

Website Coordinator: Amy Robinson amy.robinson@ew.govt.nz

Central Government Liaison: Denise Young dyoung@doc.govt.nz

Committee Member: Andrew Swales a.swales@niwa.co.nz

Administrator: Hannah Hopkins nzcoastalsociety@xtra.co.nz

NZCS Regional CoordinatorsEvery region has a NZCS Regional Coordinator who is available to help you with any queries about NZCSactivities or coastal issues in your local area.

North IslandNorthland Ben Lee benl@nrc.govt.nz

André Labonté labonte@xtra.co.nz

Auckland Hugh Leersnyder hugh.leersnyder@beca.comAlastair Senior asenior@tonkin.co.nz

Waikato Amy Robinson amy.robinson@ew.govt.nz

Bay of Plenty Reuben Fraser Reuben.Fraser@envbop.govt.nz

Hawke’s Bay Neil Daykin Daykin@hbrc.govt.nz

Taranaki Erin Zydervelt erin.zydervelt@trc.govt.nz

Wellington Iain Dawe iain.dawe@gw.govt.nz

South IslandUpper South Island Eric Verstappen eric.verstappen@tdc.govt.nz

Canterbury Justin Cope justin.cope@ecan.govt.nz

Otago Mike Hilton mjh@geography.otago.ac.nz

Southland Ken Murray kmurray@doc.govt.nz

CoastalNews

Coastal News No. 4614

assess spatial heterogeneity in this distributionand how this variability is affected by macrobenthicfauna. Most importantly, rapid surveys of theseafloor underneath marine farms with our sedimentprofile imaging device can now reveal the depthand the size of the farm AVS footprint and howthese change over time.

Our new technique makes AVS an accessibleparameter for rapid assessment of the effects oforganic enrichment in marine sedimentaryenvironments. To assess these effects, marineconsultants have been using a number of techniquesthat deal with selected functions of the marineecosystem.

We believe that the inclusion of AVS measurementsinto current monitoring practices will be an importantstep towards a more holistic and integrated approachto routine monitoring.

Reference

Bull, D C and Williamson, R B, 2001. “Predictionof principal metal-binding solid phases in estuarinesediments from color image analysis”, Environmental

Science & Technology 35, pp.1658-1662.

Organic enrichment of coastal sediment is of interestto coastal managers worldwide. It results fromexcess supply of organic carbon to coastal watersfrom both natural and anthropogenic sources suchas, terrestrial runoff, eutrophication, and aquaculture.

A large fraction of this carbon is mineralised bysulfate reduction, a bacterially mediated reactionthat leads to the production of hydrogen sulfide(H2S). This is the culprit for the ‘rotten egg’ smellyou encounter when digging up estuarine sediments.H2S readily reacts with sedimentary iron compoundsto form iron sulfides that contribute to the distinctblack colouration of organic-rich sediment.

In the laboratory, we can convert the majority ofthese iron sulfides back into H2S by adding acidto the sediment and so indirectly measure theconcentration of the acid volatile sulfides (AVS).Although this concentration is well suited as anindicator of organic enrichment, its measurementhas not been used in routine monitoring becauseof its laborious nature.

Almost 10 years ago, Bull and Williamson (2001)tested an easier approach to predict the sedimentAVS concentration from sediment images taken inthe laboratory. The authors analysed photographsof sediment sections and found a weak linearcorrelation (r2 = 0.67) between sediment colourand AVS concentration. During the past 12 months,with the help of new technology, we improved andfurther developed this approach into a rapidtechnique for monitoring the in situ distribution ofAVS.

Using H2S microelectrodes, we established a stronglinear correlation (r2 = 0.93) between sedimentcolour and the concentration of AVS. This allowsfor the accurate prediction of the distribution ofAVS from a sediment profile image. We also testedthe suitability of a novel sediment profile imagingdevice (SPI-Scan, Benthic Science; Figure 1) toobtain high-resolution sediment profile imagesreadily in the field. Our new image analysingprocedure allows us to make two types of predictionsfrom the acquired images with a simple mouseclick. Firstly, the colour intensities of horizontallyaligned pixels are averaged to obtain a verticalAVS concentration profile (Figure 2a). Secondly,individual pixel colour intensities are mapped tocreate a two dimensional distribution plot of AVSconcentration (Figure 2b).

Both types of predictions provide parameters wellsuited to environmental monitoring, for example,an assessment of the environmental impact ofmarine farms. The maximum AVS concentration andthe depth at which this occurs are readily visibleon the vertical AVS concentration profile. The twodimensional AVS distribution plot can be used to

Monitoring Organic Enrichment ofCoastal Sediment

Peter Wilson and Kay Vopel, Auckland University of Technology

Figure 1: The SPI-Scan instrument used to obtain

high-resolution in situ sediment profile images.

Want Coastal News in colour?While cost restricts our ability to print Coastal

News in colour throughout, we would remindmembers that full-colour versions are availableon the Coastal Society website. You will needto log in to access the latest issue, but back

issues (from Issue 6, April 1996) are freelyavailable.

Visit www.coastalsociety.org.nz and follow the‘Publications’ link on the front page.

CoastalNews

April 2011 15

Figure 2: (a) Example of an in situ sediment profile image. Small black and white bars on the scale to

the right of the picture are 1 mm each, the larger bars are 10 mm. The image is overlaid with the predicted

AVS concentration profile. (b) A two-dimensional AVS distribution plot derived from the image in (a).

EDS Coastlines Conference

The EnvironmentalDefence SocietyConference Coastlines(Auckland, 1 to 2 June

2011) will examine spatial planning of New Zealand’scoasts, lakesides and oceans.

Marine spatial planning is becoming a keymechanism for the implementation of oceans policyin many other developed countries. The conferencewill explore this international thinking and experiencealong with recent scientific developments andprofessional practice in New Zealand.

Sessions planned for the first day of the conferenceinclude international experience in coastal andoceans management, the case for oceans reformin New Zealand, implementation of the New ZealandCoastal Policy Statement, and a Leaders’ dialogue.

Sessions on the second day will focus more closelyon the practical application of spatial planning tocoasts, lakesides and oceans. There will be a field

Upcoming Conferencestrip, which will consist of a cruise around the innerHauraki Gulf viewing coastal management issues,on the afternoon of Tuesday 31 May.

The programme is currently under development andregular updates will be posted on the conferencewebsite.

For further details, programme information, andregistrations see www.edsconference.com.

Coasts and Ports 2011

Mark your calendars nowfor Coasts and Ports 2011which will be held 28 to30 September 2011 inPerth, Western Australia.The conference is anamalgamation of the 20th

Australasian Coastal and Ocean Engineeringconference and the 13th Australasian Port andHarbour Conference. Hosted by the NationalCommittee for Coastal and Ocean Engineering(Engineers Australia), PIANC Australia and the Instituteof Professional Engineers New Zealand (IPENZ), theconference is also supported by the New ZealandCoastal Society.

The Coasts and Ports Conference series is the pre-eminent forum in the Australasian region forprofessionals to meet and discuss issues extendingacross all disciplines related to coasts and ports.Coasts and Ports 2011 will bring together engineers,planners, scientists and researchers to focus on thetechnological, scientific, policy, planning and designissues related to our diverse and developing coasts.

For further details, programme information, pre-conference short courses and registrations, seewww.coastsandports2011.com.au.

CoastalNews

Coastal News No. 4616

New Zealand Coastal SocietyCorporate Members

Corporate membership enables organisations andcompanies to become part of the New ZealandCoastal Society and support the society’s missionof taking a leading role in facilitating a vibrant,healthy and sustainable coastal and oceanenvironment.

Organisations and companies can show their supportfor the aims and activities of the society and achievepublic recognition of that support.

Corporate membership benefits include:

• High-profile listing as a corporate membersponsor on the NZCS website(www.coastalsociety.org.nz/Corporate.htm).

• Website listing of services provided by corporateorganisation, contact details, and links to recentprojects or corporate member website.

• One free individual membership for the personnominated as the corporate contact or anysubsequent replacement alternate.

• Five complimentary copies of Coastal News

published three times per year – April, July andNovember.

• Discounted registration at member rates forthe corporate contact to all NZCS conferences.

• Short feature on a corporate member in theCoastal News newsletter.

For more information on corporate membershipsplease contact:

Kath CoombesMembership CoordinatorCoastal Society Committeekath.coombes@aucklandcouncil.govt.nz

The New Zealand Coastal Society would like to acknowledgeour corporate members for their support:

Each issue, Coastal News features a Corporate Member profile on this page.

Promote your company or organisation to over 300 professionals in the coastalscience, engineering and planning disciplines, including those employed in the

engineering industry, local, regional and central government, researchcentres and universities.

To find out how, see below.