Usipa Management Strategy for Southeast and Southwest Arms of Lake Malawi and Lake Malombe

Date: December 2018

Prepared by the Malawi Department of Fisheries and the Coastal Resources Center of the University of Rhode Island.

Cover Photo Credit: Maggie Daugherty, Pact, January 2018. A fisherman makes his way onto lake Chiuta, Malawi after a rainstorm has passed.

ACKNOWLEDGEMENTS

This work is a joint effort among key stakeholder institutions, namely the Department of Fisheries, the Coastal Resources Center of the University Rhode Island, and local fisheries management authorities such as Beach Village Committees and Fisheries Associations. We are grateful for the financial support from United States Agency for International Development (USAID) through Fisheries Integration of Society and Habitats (FISH) Project.

CITATION

FISH (2018). Usipa Management Strategy for Southeast and Southwest Arms of Lake Malawi and Lake Malombe. USAID/FISH Project, Pact Publication, Lilongwe, Malawi: p. 11.

DISCLAIMER:

Prepared under USAID Cooperative Agreement No. AID-612-A-14-00004, awarded on September 9, 2014, entitled Malawi Fisheries Integration for Society and Habitat (FISH) Project. This report is made possible by the generous support of the American People through the U.S. Agency for International Development (USAID). The contents are the sole responsibility of Pact, Inc. and FISH and do not necessarily reflect the views of USAID or the United States Government.

CONTACT ADDRESS

Pact Malawi, Pact Inc. 1st Floor, Amina House, 1828 L Street NW, P.O. Box 1013, Suite 300, Lilongwe, Malawi, Washington, DC 20036, Phone: +265-1751220; +265-1751201, USA. e-mail: infomw@pactworld.org +1-202-466-5666

Abbreviations and Acronyms BVC Beach Village Committee

CFA Commercial Fishers Association

CRC Coastal Resources Center

DAES Department of Agriculture Extension Services

DoF Department of Fisheries

F40% Fishing at 40% of the total yield capacity

FA Fisheries Association

FISH Fisheries Integration of Society and Habitats

Fmax Fishing at maximum yield

LFMA Local Fisheries Management Authority

LUANAR Lilongwe University of Agriculture and Natural Resources

MGDS Malawi Growth and Development Strategy

MFRS Monkey BayFisheries Research Station

MoAIWD Ministry of Agriculture, Irrigation and Water Development

NFACS National Fisheries and Aquaculture Communication Strategy

OVI Objectively Verifiable Indicators

PFM Participatory Fisheries Management

SADC Southern African Development Community

SAV Submerged Aquatic Vegetation

SEA South East Arm

SPR Spawner Per Recruit

SSBPR Spawner Stock Biomass Per Recruit

SWA South West Arm

URI Universty of Rhode Island

USAID United States Agency for International Development

YPR Yield Per Recruit

Contents

Preface .................................................................................................................................. i

1. Background .......................................................................................................................1

1.1 Introduction to this Document ................................................................................................................. 1

1.2 The Process ............................................................................................................................................... 1

2. Background to the Problem ............................................................................................. 2

2.1 The National Importance of Fish and Usipa ........................................................................................... 2

2.2 Usipa Biology ............................................................................................................................................ 3

2.3 Fishery Profile .......................................................................................................................................... 4

2.3.1 History of Exploitation ....................................................................................................................... 4

2.3.2 Description of Principal Gear ............................................................................................................. 4

2.4 Principal Factors Affecting the Usipa Fishery ........................................................................................ 4

3. Usipa Management Strategic Plan ................................................................................... 5

3.1 Strategic Objectives .................................................................................................................................. 5

3.1.1 Stakeholder Objectives ........................................................................................................................ 5

3.2 Guiding Principles .................................................................................................................................... 5

3.3 Expected Outputs ..................................................................................................................................... 6

3.4 Action Plan................................................................................................................................................ 6

4. The Way Forward ............................................................................................................. 8

4.1 Management Authority ............................................................................................................................ 8

4.2 Funding Support ...................................................................................................................................... 8

4.3 Short-term Action Plan ............................................................................................................................ 8

4.4 Usipa Management Strategy 2018-2025 ................................................................................................ 8

5. Appendix 1. Usipa Yield per Recruit and Spawning Stock Biomass Per Recruit .............. 11

5.1 The Models ............................................................................................................................................... 11

5.2 Usipa Parameters ................................................................................................................................... 12

5.3 Results ..................................................................................................................................................... 13

5.4 References ............................................................................................................................................... 14

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Preface This Strategic Plan is intended to guide the management of the Usipa fishery in Lake Malawi and Lake Malombe. This document mainly focuses on Lake Malawi since there is paucity of information for Lake Malombe. The production of this document has been made possible by the following stakeholders the Department of Fisheries (DoF), Beach Village Committees (BVCs), Fisheries Associations (FAs), and individual fishers and processors/traders. This work was made possible with funding from USAID through Fisheries Integration of Society and Habitats (FISH) Project. It is our sincere desire to see Usipa managed in a sustainable way to provide continued employment and food resources for all of Malawi to help reach the vision as stated by the stakeholders: “Working together to have a robust Usipa fishery that supports food and income security for the benefit of all Malawians now and for the future.” This document is an annex to the ecosystem-based Management plans for the fisheries of Southeast and Southwest arms of Lake Malawi, Upper Shire, and Lake Malombe.

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1. Background

1.1 Introduction to this Document Usipa was identified as an important fishery which currently contributes over 70% of total landings in Malawi. However, this fishery is currently unmanaged. New information has emerged from the literature regarding small pelagic management and the need for management, especially in the years when recruitment is low. The need to maximize yield from this fishery is becoming a critical issue especially since other species abundance has been depressed.

In order to ascertain the direction for management, a literature search on Usipa was first performed to prepare a scientific report. Concurrently, a survey of local fishers’ knowledge on Usipa was conducted in several communities of Lake Malawi. This information was combined into a synthesis document where areas of consensus or discord were identified, and research gaps were listed. Data on Usipa length frequency was collected by a team of researchers from the Monkey Bay Fisheries Research Station (MFRS) and Lilongwe University of Agriculture and Natural Resources (LUANAR), funded by USAID through the FISH project. The data was analyzed during Stock Assessment Training held in Chilema in August 2017. The Government of Malawi introduced the decentralized fisheries management approach that is currently being operationalized as Participatory Fisheries Management (PFM). Fisheries Associations (FA) have been created at the ecosystem level to empower communities to work in partnership with government in formulating and implementing fisheries by-laws, development and management plans. This is also in tandem with the ecosystem approach to fisheries management. The FAs took the lead on meeting with communities to discuss management options that are included in this document.

1.2 The Process The Usipa Strategy document has been a joint initiative between the FISH project, the Malawi Government through DoF, and the fisheries stakeholders. There have been three main activities to create this plan:

1. Basic data on Usipa was obtained from literature review and local knowledge that is available as a scientific synthesis document.

2. Stock assessment data collection was conducted from May 2016 to May 2017. Lengths of fished Usipa was collected in 5 sites monthly by a team from FRS and LUANAR. The collected data was processed during a stock assessment training session in July 2017 and a full report was generated. This information has been added to this strategy document.

3. A leadership training was conducted in May 2017 with the newly elected FA’s and others from the

DoF, trawlers association, women processers and fishermen. After this training, management options were collected from stakeholder by FAs and brought together during a management meeting in July 2017. These have been added to this document.

4. The draft strategy document was (and will continue to be) vetted with stakeholders and DoF.

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2. Background to the Problem

2.1 The National Importance of Fish and Usipa Malawi’s fisheries sector plays a significant role in the economics, politics, and social dynamics of the nation, providing direct employment for over 60,000 fishers and more than 450,000 fish processors, distributors, and others involved in the domestic fish trade. Fish are a major source of protein for Malawians and serve as an important safety net during times of drought and heightened food insecurity. In light of its profound national importance, the fisheries sector has often provoked broad-based disputes over access to and stewardship of its valuable resources from a diverse body of stakeholder groups and institutions. Usipa has recently become the dominant fish and fishery in Lake Malawi. The reasons for the boom in production are many and uncertainty exists about short and long -term ecosystem responses. Fishermen have been quick to change their fishing methods to take advantage of this shift in biomass but are also concerned about the future of this fishery, as well as some of the more lucrative traditional fisheries. Usipa appear to be a critical component of the ecosystem. Since Usipa is both a food source for other species and a major predator on plankton species, they may quickly respond to changes in environmental factors and climate change. The southern end of Lake Malawi (Figure 1) is comprised of the Southeast Arm (SEA) and Southwest Arm (SWA). The SEA has a total surface area of about 2000 km2 and is the shallowest part of the lake. Winter mixing caused by seasonal southeast winds and upwelling drives the thermocline to the bottom, causing the entire water column to mix and bring up the nutrient rich bottom water. Mixing occurs in the entire SEA area, resulting in very high phytoplankton in the area and as a result the SEA supports a much richer fishery and has the highest production per unit area of the entire lake. In recent years, the area has accounted for about 60% of the annual fish landings from Lake Malawi even though it represents only 10% of the total surface area of the lake. Lake Malombe comes off the SEA of Lake Malawi (Figure 2) and is a natural lake that covers a surface area of 310 km2, has an average depth of 4 meters. It contains a total water volume of 1 km3 and has a total shore

Figure 1: Map of Lake Malawi showing the Southeast Arm and Southwest Arm (Maguza-Tembo 2004)

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line of 91 kilometers. The lake, which sits at an elevation of 473 meters, drains a watershed that covers 130,759 km2 and has a residence time of 13 days. There are many challenges facing the Usipa fishery today: open access; limited information and monitoring, especially of the commercial sector; unknown potential harvesting capacity of the artisanal sector; poor prices paid to fishermen; waste and inefficiencies including high post-harvest losses, as well as poor sanitary conditions at landing sites. The sustainability of the fishery will rely on using an active and logical participatory approach to limit harvest rates and collect appropriate data to manage this diverse fishery.

2.2 Usipa Biology Usipa, the lake sardine (Engraulicypris sardella) is an African species of freshwater fish in the Cyprinid family (Figure 3). The management of short lived small pelagic species, like Usipa, requires a different approach that recognizes the variability in the environmental system as the major driver of population size. These species play critical roles in ecosystems at many space and time scales. There is evidence of a bottom up control where Usipa occupies a crucial intermediate trophic level and serve as important forage fish and that fluctuations in primary productivity would determine the strength of the year class. There is also evidence for top down control where predators exert pressure and control year class strength (at larval stages). Fishermen point to actual changes in abundance as a result of environmental conditions on the Usipa stock. Therefore, it is believed that management strategy will play an important role in Usipa sustainability. There are still some research needs that should be addressed but moving forward with this strategy plan is an important first step.

Figure 3: Specimen of Usipa fish

Figure 2: Map showing the Southeast arm, Upper Shire and Lake Malombe

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2.3 Fishery Profile

2.3.1 History of Exploitation Usipa catches have been steadily increasing since 2004 and the fishermen have reported a decline in catch rates per individual fisher in recent years. Fishing for Usipa in Lake Malawi occurs primarily in the Southeast and Southwest Arms which are the most productive regions of the lake. Recent study findings show that stocks of Usipa in these areas are currently undergoing overfishing.

2.3.2 Description of Principal Gear The main gears used to harvest Usipa are the Chilimira net, Kambuzi seine, and Usipa seine net. These three gears combined have accounted for approximately 89 to 100% of the total catch of Usipa since 1976. The Chilimira net is classified as an open water seine. Generally, the overall trend in the number of Chilimira nets has been stable since 2009. There was an increase from 2014 to 2015 of almost 18%. The Kambuzi seine and Usipa seine net are categorized as beach seines. There has been a decline in the number of Kambuzi seines while the number of Usipa seines has been stable. From the current stock assessment, there is overfishing in SEA and SWA of Lake Malawi.

2.4 Principal Factors Affecting the Usipa Fishery Several critical factors are believed to be main drivers in the Usipa fishery:

a. Lack of alternative employment and /or fish species to fish leading to high demand for Usipa. b. Overfishing, use of illegal gear, lack of adherence to existing rules and regulations. c. Habitat destruction: Removal of submerged aquatic vegetation (SAV), changes in water quality

from runoff, fertilizers. Multiple uses for farming, hotels, and tourism. d. Changes in the environment due to climate change such as erratic rainfall and wind patterns. e. A dominant single species fishery is more vulnerable to ecological variations and a likely

irreversible change to the ecosystem will impact upon the Usipa stock and the fishery.

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3. Usipa Management Strategic Plan

3.1 Strategic Objectives The long-term sustainability of the Usipa fishery is tied very closely with restoration of other species such as Mcheni (Rhamphochromis spp) and Kampango (Bagrus meridionalis). Mcheni and Kampango are the primary predators of Usipa along the food chain. Therefore, gears that target Usipa also catch these predatory species. The strategic objectives of the Usipa fishery are therefore based on biological and exploitation regimes. Many of the reference points used are a result of the Yield per Recruit (YPR) and Spawning Stock Biomass per Recruit (SSBPR) analysis (Appendix 1) that was used as a basis of discussion for the stakeholders.

3.1.1 Stakeholder Objectives

Biological Objectives

1. Increase spawning stock biomass to SSBPR 40% from 11% in 5 years. 2. Increase Usipa yield by reducing fishing effort from 0.5 to 0.3 in 5 years. Currently 86% of the fish

are removed from the population every year. The new target is to reduce removal rate to 67% (corresponds to Fmax).

Ecological Objectives

1. Protect lake from ecological disruption caused by fishing operations and other anthropogenic activities.

Economic Objectives

1. Increase individual income to fishers and traders from sustainable production of Usipa by 20% in 5 years.

Social Objectives 1. Increase compliance with existing regulations and laws. 2. Increase collaboration between artisanal fishers, large scale fishers, state and non-state actors.

3.2 Guiding Principles The following are the guiding principles of the Usipa Management Strategic Plan:

a. Recognizing that fish play a very important and strategic role in food security and that fish significantly influences the health, mental and development growth of Malawi’s poor, especially the youth, fish catches must be sustained and/or increased.

b. Recognizing that Usipa constitutes more than 70% of total fish production supporting a majority of 1,600,000 people along the value chain. Acknowledging that reduction in fishing effort may create adverse economic conditions for fishing communities, therefore, full political support is essential if this strategy is to succeed.

c. Recognizing that the Strategy document should not be a standalone initiative, but an

integrated, cross-sectorial approach, all activities must be tangible, do-able and achievable. The

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strategy must become an integral part of DoF and MoAIWD, on-going sector development plans, Malawi Growth and Development Strategy III (MGDS III) and needs to be effected under the Decentralization Act.

Recognizing that the main threats to sustainable management of Usipa are believed to be overfishing caused by open access and ineffective participatory fisheries management, poor enforcement of regulations and illegal fishing operations; sustainable Usipa production will depend on effective implementation of the six policy co-management steps.

d. Recognizing that natural resources have been constantly undervalued, government has been unable to fund its intervention. Malawi has a tax-based economy but the fishery remains in the informal economy. The Government must collect adequate revenue from people harvesting fish so as to be able to restore the damage done. The Government shall adopt the principles of a fair and equitable license fee system based on the value of the resource and the cost to rehabilitate it. The Department of Fisheries shall collect license fees and penalty fees and retain a portion in its Fisheries Fund for further capacity development of the Department and local fisheries management authorities (LFMAs).

e. Recognizing that fisheries is a system with its ultimate goal to provide food to the consumer,

none of the principles above will be successful unless the people of Malawi are aware of the importance of Usipa to their well-being, a massive awareness and political campaign to manage the fishery must be implemented. All walks of life need to be made aware of the status of the fishery and reasons for the threats so that they can be called upon to act responsibly to enforce this strategy.

f. Finally, it must be recognized that any strategic response must be within the framework of

international and national guidelines as laid down in the Conventions to which Malawi is signatory, notably Convention on Biological Diversity and SADC Protocols for Shared Water Bodies among others.

3.3 Expected Outputs By 2018, the Usipa Strategic Plan will be a living document allowing for adaptive management. This effectively means that each year it should be revisited and assessed for effectiveness. The implementation of this strategy will achieve the following outputs.

By 2020, the YPR shall be at the threshold reference point, Fmax whereby the maximum yield is obtained from the stock production.

By 2025, the SSBPR shall be at F40% which should provide protection from poor spawning years.

3.4 Action Plan

Strengthen Organizational Frameworks

Establish the decentralized structures and processes for management authorities

Issuing of licenses and registration by the district council

Amend by-laws to include rules and regulations addressing Usipa

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Incorporate Usipa Strategy document into Lakes Malawi and Malombe Management Plans

Empower LFMAs to enforce and encourage voluntary compliance. Assist them to develop alternative strategies for livelihoods in short term and long term.

Assist the reorganization of CFA and its membership to ensure self-regulation and compliance

Research Program

Continue to monitor status of Usipa stocks through artisanal and large-scale fishery dependent survey

Gather data and information on Usipa from Lake Malombe to enrich the Usipa Strategy document

Continue and enhance support for data systems, adequate hardware and training opportunities on stock assessment

Promote Sustainable Use

Work with all stakeholders to develop balanced vision for sustainable exploitation and utilization of the Usipa fishery

Develop behavior change strategies for short and long-term objectives

Revisit and evaluate Usipa management harvest strategies and impacts

Develop Effective Management Tools

a. Reduce effort to leave more adult reproducing Usipa b. Protect spawning areas during breeding season c. Establish sanctuaries d. Ban and/or enforce the ban on small meshed gear such as mosquito nets, use of mosquito nets in

bunt and in trawl cod end liners e. Reduce the purchase and sale of small fish by traders and processers f. Protect nursery areas and vulnerable habitats such as reeds and SAVs g. Educate consumers on Usipa and its management strategy h. Provide sufficient buffer zone area: Reduce runoff by planting trees and ban farming on lake shore.

Involve Department of Agriculture Extension Services (DAES) in fisheries discussions i. Reduce use of destructive fishing gear (heavy sweeps or other gear that might disrupt bottom).

a. Update on fishing gear by DoF b. Fisheries extension to change foot rope designs with fishermen

j. Restore balanced ecosystem overall. Connect species management under the ecosystem approach. Institute ecosystem management plans

k. Reduce post-harvest loss and increase quality and safety of product. l. Conduct research on Usipa value addition m. Reduce fishing effort (nets, tilly lamps, etc.) n. Conduct research on emerging fishing technologies targeting Usipa (e.g. LED and Paraffin lamps) o. Enforce registration of fishers and gears; and licensing of fishing gears and crafts p. Voluntary non-purchase of fish caught illegally

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4. The Way Forward

4.1 Management Authority

The implementation of the Usipa Strategic Plan will feed into the Lake Malawi Management Plan which is implemented by the Mangochi District Council.

4.2 Funding Support

Funding will come from licenses, fees, fines, central government allocation and other stakeholders.

4.3 Short-term Action Plan

The following are the short-term actions required to set this plan in motion:

2017-2018: Draft strategy plan is reviewed and finalized. FAs develop action plans for behavior change with LFMAs.

2018: Policy paper is finalized and decentralized management is in place.

2018: FA continue to engage with stakeholders and local level is engaged in regulations and enforcement.

4.4 Usipa Management Strategy 2018-2025

Vision: Working together to have a robust Usipa fishery that supports food and income security for the benefit of all Malawians now and for the future. Goals: To use co-management to effectively manage the Usipa fishery. Objectives:

Increase spawning stock biomass to SSBPR40% from 11% in 5 years.

Increase Usipa yield by reducing fishing effort from 0.5 to 0.3 in 5 years. Currently 86% of the fish are removed from the population every year. The new target is to reduce removal rate to 67% (corresponds to Fmax).

Protect lake from ecological disruption caused by fishing operations and other anthropogenic activities.

Increase individual income to fishers and traders from sustainable production of Usipa by 20% in 5 years.

Increase compliance with existing regulations and laws.

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# Objectives Strategic Action OVI Where? By Whom By When Assumptions/Constraints

1 Increase spawning stock biomass to SPR40%

from 11% in 5 years

Reduce use of under-meshed gears Protect spawning areas

Reduction in number of under-meshed gears by 40% 39 spawning areas covering 1440ha protected

Southern Lake Malawi and Lake Malombe

DoF, LFMA, District Council

2023 Limited financial resources Willingness to participate by communities

2 Increase Usipa yield by reducing harvesting rate (E) from 0.5 to 0.3 in 5 years

Increase penalties on mosquito nets and other illegal gears by confiscating mosquito nets and charging fine of MK50,000 Increase fines for chilimira and nkacha nets from MK60,000 to MK150,000 Increase licensing fee on Chilimira from MK25,000 to MK40,000

Reduced harvesting rate (E)1 from 0.5 to 0.3 Currently 86% of the fish are removed from the population every year. The new target is to reduce removal rate to 67% (corresponds to Fmax). Number of chilimira fishers reduced by 25%

Southern Lake Malawi and Lake Malombe

DoF, LFMA, District Council, individual fishers

2023 Limited financial resources Political will Willingness to participate by communities

3 Increase income to individual fishers and traders from sustainable production of Usipa by 20% in 5 years

Educate and inform on improved fish processing technologies and onboard fish handling Conduct research on Usipa value addition

Reduce post-harvest losses by 20% Number of value-added products

Southern Lake Malawi and Lake Malombe

DoF, LFMA, District Council, individual fishers DoF, LFMA, District

2023 Financial resources FRS capacity

1 Harvesting rate (E): The ratio of all human-induced removals to the total exploitable stock size

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Reduce cost of fishing

New rules on catch quotas

Southern Lake Malawi and Lake Malombe

Council, individual fishers

Willingness to adopt by processors and consumers.

4 Increase compliance with existing regulations and laws

Conduct awareness campaign Conduct training Enforce existing regulations and laws

Number of awareness campaigns and trainings conducted Number of patrols conducted Percentage of fishers complying

Southern Lake Malawi and Lake Malombe

DoF, LFMA, District Council, individual fishers, Navy, Marine Police,

2023 Financial resources Willingness of stakeholder/institutions to participate Adoption NFACS

5 Increase collaboration between artisanal fishers, large scale fishers, state and non-state actors

Strengthen organizations Conduct team building exercise through visioning

Number of leaders trained Number of collaborative meetings and joint action plan

Southern Lake Malawi and Lake Malombe

DoF, LFMA, District Council, individual fishers

2018 Financial resources Willingness of stakeholder/institutions to participate

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5. Appendix 1. Usipa Yield per Recruit and Spawning Stock Biomass Per Recruit

The Yield per Recruit (YPR) and Spawning Stock Biomass per Recruit (SSBPR) models were used to supplement the length-based stock assessment done on Usipa in 2017. Because of the uncertainty of parameters, they were not used as part of the stock assessment but can be a useful guide for developing management strategies.

5.1 The Models YPR models can be used to predict the effects of alterations in harvesting activity on the yield available from a given year class. The two elements that define the model are the fishing mortality (F) and the pattern of harvesting activity on different size/age fish. To predict the yield, parameters characterizing the life history of the given species must be used. These include:

K is the instantaneous growth coefficient from length-based assessment M is the instantaneous natural mortality coefficient from Hewitt and Hoenig (2005) Linf in the maximum length an individual fish may attain obtained from length-based assessment L W relationship (a and b) from FISHBASE Maturity curves by age (assumption)

Fishery related factors:

Tc is the age at which the fish enters the fishery with selection curve (calculated from length-based assessment) F is the instantaneous fishing mortality coefficient (calculated from length-based assessment

The model starts with 1000 fish and the subsequent decrease in number over time by natural and fishing mortality is defined using the decay function. A selectivity function is added to account for gear interactions. This discrete time model uses steps of 0.1 years. Fish length is converted to age. Yield at each age/length is simply the number remaining x the weight. This is run for all F levels to produce the YPR curve. A SSPBR model is also added to the YPR by putting in a maturity function showing percent maturity at each time step, which is also multiplied by the number remaining in the population. Percent SSBPR is obtained by dividing by the SSBPR at 0 fishing mortality.

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5.2 Usipa Parameters There are many parameters that are unknown for Usipa. Many assumptions have been made to run the simple YPR and SSBPR models. Age: The age has been determined by using the inverse Von Bertalanffy equation. L∞ and K are provided from FiSAT II using length frequency of the samples over the year to calculate growth. K=0.58 L∞= 14.175

𝑡 = 1𝐾⁄ 𝑙𝑛 (

𝐿∞(𝐿∞ − 𝐿𝑡)⁄ )

Mortality: The natural mortality of the Usipa was determined with the Hessler and Hoenig equation where M = 2.98/agemax where agemax = 1.5 years. M alone occurs when selectivity is equal to 0. Otherwise Z=F+M. Selectivity: The selectivity of the gear is considered to be minimal starting at Age = 0 and rising linearly until reaching 100% at about 3 months of age. Changing this parameter through management is the most effective method for increasing yield and spawning stock biomass.

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Weight: The weight and length relationship was obtained from FISHBASE where a= .0041 and b = 3.07. Maturity: Thompson et al. (1996) described spawning state of the Usipa in the offshore areas using external and microscopic characteristics. They found developing ovaries at 7 cm TL (about year 1); Stage III ovaries (ripe) were seen in individuals between 7.8-11.8 cm TL and virtually no stage IV (running) or V (spent) were captured. FISHBASE estimates an L50% maturity between 6.6-11.8 cm TL (no sex given). There is no published information using reproductive field information about size or age at 50% maturity. There is little information about actual fecundity. For the model we used a linear function set between 0-1 and allowed for partial maturity starting at 3 months of age.

5.3 Results The following graph displays the results from the YPR and SSBPR model. All Usipa sampled were combined from the SEA and SWA for this analysis. The Fcalc is the result obtained from the length converted catch curve analysis. YPR Fcalc = 1.95 Fmax (threshold) = 1.10 The F far exceeds the threshold reference point of Fmax so overfishing is occurring with Usipa based on YPR. This also matched the result from the length- based analysis (see stock assessment report). SSBPR Current SSBPR = 11% Precautionary SSBPR = 40% SSBPR is extremely low for this fishery. Mace (1994) recommended that when the S-R relationship is unknown, F40% be adopted as a target fishing mortality, but that it be adjusted to accommodate any known or assumed degree of density dependence in the S-R relationship. Any management action should be directed at increasing the size of the spawning stock especially since the stock recruitment relationship is not known.

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5.4 References Hewitt, D.A. and J.M. Hoenig. 2005. Comparison of two approaches for estimating natural mortality based on longevity. Fishery Bulletin 103:433-437. Mace, P. 1994. Relationships between common biological reference points used as thresholds and targets of fisheries management strategies. Canadian Journal of Fisheries and Aquatic Sciences 51: 110-122. Thompson, A.B., Allison, E.H., and B.P. Ngatunga. 1996. Distribution and breeding biology of offshore pelagic cyprinids and catfish in Lake Malawi/Niassa. Environmental Biology of Fishes 47: 27-42.

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F40%=0.69

Fcalc=1.95

11%