8A � Sunday, February 9, 2014 BAY CITY TRIBUNE � baycitytribune.com

“Oyster reefs serve as an eco-logical environment for a num-ber of marine species,” he said.“You have other kinds of ani-mals such a crabs that can usethat environment as well asother crustaceans. It can alsoserve as a nursery for suchspecies as shrimp and smallfish; which in turn will attractthe larger fish. It’s a very exten-sive interaction.”“There are going to be times

when the conditions are not per-fect for oysters,” NCTAssociate Director ofMarketing Vanessa Miller said.“But even then it is designed tocontinue to provide a place forthose other species to thrive.The idea is to improve the entirebay and not just one aspect of it.And to create an environmentthat can be sustained.”According to a NCT news

release, there are additionalbenefits to be derived from asuccessful restoration amongthose are improving the waterquality of the bay.“An individual adult oyster

can filter around 50 gallons ofwater each day; a healthy one-acre reef filters approximately24 million gallons of waterdaily.With 207 estuaries and 30major rivers draining into theGulf – and an average of 40,000gallons of water flowing intoMatagorda Bay every second –oysters’ natural water filtrationprocess becomes incrediblyimportant in keeping theecosystem healthy and bal-anced.“(In addition,) the Nature

Conservancy and partners willbe producing a body of scienceon the reef to illustrate how itfares during drought conditions.Matagorda Bay is one of thelargest estuaries on the Texascoast and both the marine lifeand the bay itself require fresh-water to remain productive.Drought increases salinity lev-els in bays and estuariesbecause it reduces the level offreshwater entering into baysand estuaries from rivers,streams and rainfall. Whensalinity levels increase forextended periods of time, theestuary can become unsuitablefor many of the juvenile marinespecies that rely on it.“In 1999, the Environmental

Protection Agency reportedMatagorda Bay’s average salin-ity level as 19 ppt. However,after several years of prolongeddrought, salinity levels are aver-aging above 30 ppt. Half MoonReef will attract Eastern oys-ters, which typically thrive insalinity levels of 10 ppt to 28ppt but can survive higher lev-els. However, as salinity levelsincrease, so does the numberand size of predators and therisk of disease within oystercolonies.“A monitoring program for

this project has been underwayfor several years and theresearch indicates that the reefwill succeed despite highersalinity levels. It is also antici-pated that the reef will help con-tribute to a more resilientecosystem in the bay overall,and potentially help the bay tobetter tolerate the impacts ofdrought and low flows byimproving water quality, pro-

moting a higher abundance anddiversity of marine species andthe growth of sea grass. It’s alsoanticipated that the brood stockproduced by the reef willincrease the abundance of oys-ter colonies throughoutMatagorda Bay.“It is well known that tidal

and sub-tidal reefs near shore-lines can contribute to greatershoreline stabilization andcoastal resiliency. Oyster reefsact as natural breakwaters byproviding a natural solid struc-ture that is anchored to the baybottom. This allows the reefs toabsorb the energy from wavesand keep sediment on the bot-tom of the bay stable.“In general, natural infra-

structure like healthy reefs, wet-lands and marshes, are a cost-effective first line of defenseagainst storms and impactsfrom sea level rise. As theeffects of climate changeincrease, natural defenses canwork in concert with built infra-structure along our coastlines toprotect people, property andnature,” the release concluded.

Building materials for artif-ical reefWhile rock and stone have

been used as building materials,the best construction projectmatch the right kind of materialto kind of project being done.For the Half Moon Bay

restoration, the right materialwas not found in Texas. Insteadit was quarried in Missouri,shipped down the MississippiRiver and then sailed in bargesalong the Gulf Coast beforereaching its final destination inMatagorda Bay.

Dumesnil explained severalissues went into the decision towork with the Missouri lime-stone.“It met the specifications we

were looking for very closely,”he said. “We were looking inpart for a specific density.Sometimes limestone can betoo dense. You need for there tobe the little cracks and crevass-es to be formed to give the oys-ter sprat (eggs and immatureoysters) a place to attach them-selves.“We couldn’t use marble

because it is a softer stone so itis going to degrade quicker andthat’s even more of a problemwith something like clay.”In addition to finding the right

material, there was cost to con-sider. Working with federalfunds provided from theCoastal Impact AssistanceProgram of the U.S. Fish andWildlife Service through theTexas General Land Office,Dumesnil said any cost savingswould benefit the long-range

success of the project.“The limestone quarry was

owned by a construction com-pany located right by theMississippi River,” he said. “Itcould be cut to size, loaded on abarge and brought down theriver and the down the inter-coastal waterway to the projectsite.“To get it in Texas, you would

need to have it quarried, load itup on trucks and transport it to atrain, unload it, load it, bring itby train to this area, unload it,load it and drive it to the coastwhere youwould have to unloadit and load it on a barge. Eachtime you handle something likethat, there is a cost involved andwe had just a set amount ofmoney to work with.”Before the work was com-

pleted, some 93,600 tons oflimestone was added toMatagorda Bay.The limestone was used to

create Phase I of the restora-tion project, which was gener-ally completed in December.

“We started construction inMid-October and finishedabout a week beforeChristmas,” Dumesnil said.“With something like this,you don’t just start dumping itin the water. We do place itwith bucket cranes but there isa particular way you need itdone. There is a very specificdesign based on size and con-figuration we are looking forin the reef.”“Since this was built as a

survey project with a specificpurpose, we still need to do amulti-beam side scan withsonar to verify the work wasdone correctly. I’ve also putin some temporary buoys towarn boaters but eventuallywe are going to have to estab-lish permanent buoys signal-ing there is a submergedreef.”And the work isn’t done

once the reef is signed off on.“Then there is the monitor-

ing aspect. We’ve contractedwith the Texas A&M Systemto monitor it for the next fiveyears,” said Dumesnil.While Phase I covers 45

acres and the upcomingPhase II, using recycledwaste concrete from a cementcompany as the buildingmaterial adding another 12acres of oyster habitat,Dumesnil envisions a daywhen it might grow to HalfMoon’s historical size ofabout 5,000 acres.“Oyster reefs grow as new

oysters attach themselves tothe shells of old oysters. Soas they produce more oysters,the reef is going to naturallyincrease in size.”

REEFCONTINUED FROM PAGE 1A

Numbers at a Glance:

500 Acres – Approximate size of the original reef (as surveyed in1907)0 Acres – Current size of the reef57 - 62 Acres – Approximate size of the reef after phase one andtwo are completed (the reef will then continue to rebuild on itsown)26 – The number of reef rows The Nature Conservancy will beconstructing during phase 1650 ft. – The length of each row93,600 – Tons of limestone that will be used to construct thereef during phase 150 and 85 – the percentage of oysters that have been lost in theGulf of Mexico and around the globe, respectively$30 million – Economic impact of the Texas oyster industry24 million gals – Approximate amount of water an acre oysterreef could filter per day