Marc H. Taylor MSc. Doctoral student, project CENSOR Center for Tropical Ecology (ZMT) Bremen, Germany Exploration of marine zoning for Bahía Sechura, Perú

Study area: Bahía Sechura, Perú ~ 400 km2

► Rapid development of growout culture of the scallop Argopecten purpuratus  Requires a shift in harvest rights from open-access to private  Aquaculture is limited by seed availability  No information on the carrying capacity of the system for aquaculture enhancement  Conflicts have begun to arise as to how and where these zoning changes are to be implemented The problem:

► Identify „nucleii“ for scallop population  These will be left as an MPA for spawning stock security. ► Partition part of bay into culture area Proposal of fisheries ministry

► Environmental variability  Riverine input affects mortality during El Nino.  Riverine input may affect PP?  Strong PP from upwelling ► Advection presseses  Available PP?  Settlement processes ? Other considerations ► Cost / Benefits of zonation  Who will benefit?  How to maximize benefits? ► Mediation  River flow  PP  Seed capture  Aquaculture biomass  O2  scallop distribution

► 20 functional groups including  Detritus  2 producer groups (Phytoplankton and Macroalgae)  Zooplankton  6 benthic primary consumer groups (Polychaetes, Scallops, Sea urchins, Herbivorous gastropods, Benthic detritivores, and Miscellaneous filter feeders)  6 benthic carnivore groups (Predatory gastropods, Small carnivores, Predatory crabs, Sea stars, and Octopods)  3 fish groups (Littoral fish, Small pelagic fish, and Pelagic predatory fish)  2 top predatory groups (Marine mammals and Sea birds). ► Additional changes  Multistanza – scallops  Aquaculture biomass  Dummy groups – DO2, River input, SST Base Model

► To model the implementation of several types of zoning strategies ► Goal: Maximize user benefits Ecospace

► Sandy 0-10m ► Sandy 10-20m ► Silt 20-35m ► +35m ► Aquaculture Habitats 5.35 °S °W °W 5.90 °S Cell size: 0.01 x 0.01 deg

► Benthic resources confined to habitats above 35m due to anoxic conditions at lower depths Defining habitats

► Spawning stock (scallops) MPAs 5.35 °S °W °W 5.90 °S

► Fishing – all but aquaculture areas ► Diving – all areas +30m (may separate later into open- access and Aquaculture) ► Seed Collection – sandy habitats (main recruitment habitat) plus aquaculture areas ► Aquaculture – aquaculture areas ► River – dummy mediation variable (forced with effort, E)  Now linked only to PP Rules for Fishery fleets

Results

► Explore other MPA‘s (size and location) to enhance seed availability / benefits ► Include Isla Lobos de Tierra – explore sources / sinks of scallop populations  Would require a third multistanza for advected scallop larvae Prospects

►... Prospects