Biodiversity and Fisheries Management

Biodiversity and Biodiversity and Fisheries Management Fisheries Management

Daniel PaulyDaniel Pauly

Fisheries Centre, Fisheries Centre,

University of British ColumbiaUniversity of British Columbia

Vancouver, CanadaVancouver, Canada

United Nations Fisheries Training ProgrammeUnited Nations Fisheries Training Programme

Marine Research Institure, Marine Research Institure,

December 17, 2002, Reykjavik, IcelandDecember 17, 2002, Reykjavik, Iceland

Frankly it is not obvious how ‘biodiversity’ can be included into fisheries management, even if the latter becomes ecosystem-based. However:

• Most of the world’s countries have signed on the Convention on Biological Diversity, and similar agreements and treaties, and these require considering biodiversity when managing fisheries; and

• Even without this formal reason, we should in any case attempt not to lose species and other genetic resources.

For example, we would not want to lose any of the species of the Icelandic marine ecosystem

Through this presentation, I will therefore suggest one approach that can be used to assess biodiversity in an ecosystem context, assuming that this can thus inform fisheries management. The steps are: • Construct, using the Ecopath software, a food web model

of the ecosystem of interest, and including functional groups representing all of the system in question;

• Identify/list the species included in each functional group;• Incorporate the status (IUCN Red List, CITES, etc.) of

these species as constraint into policy explorations conducted with Ecosim (e.g. via ‘Mandated Rebuilding’ or Ecospace (e.g. via Marine Protected Areas);

• Formulate policies that account both for fisheries benefits and for maintenance of biodiversity.

We have discussed previously how to construct an Ecopath model, and need not return to this here….

The next items is the area covered by the model. Let’s assume it is a Large Marine Ecosystem (LME)…

And let’s assume we select the Arabian Sea (which is a bit large)…

First things first: we can link directly to FishBase to list the fishes occurring there…

For many of these fishes, we will have access to parameters relevant to model building, e.g. on growth.

…and on diet composition, i.e., trophic levels (as also needed for analyses of ‘fishing down.’

Indeed, these trophic level estimates allow us to construct simple ‘pyramid’ models of ecosystems.

Once the fishes are covered, we can move on to other groups, e.g., the cephalopods (squids, cuttlefishes, etc.).

We have added to CephBase a structure enabling it to output LME and country lists…

…the trick being to interface maps of their distribution with LME and EEZ maps.

Octopus globosus

Other groups will follow, notably macroalgae..

Though here, there is still a big job to do with assignments to LME and EEZ.

This also applies to Reptiles (marine turtles, sea snakes, etc.)…

This biodiversity is what support fisheries landings, which must be re-expressed on a per- area basis…

…while temperature and other environmental parameters also need to be considered…

Notably, Chlorophyll a…

and especially Primary Production.

Then we incorporate other things we know about the system, e.g., from the NOAA website on LME…

We intend to replicate the work presented here at LME level at the finer level of countries EEZ. This should allow for:

• A finer resolution, for both biodiversity lists, and for Ecopath models, which will lead to countries being better able to document their marine biodiversity;

• A better understanding to be achieved regarding the relationships between biomass fluxes and the biodiversity they support.

There is obviously more to incorporating biodiversity into fisheries management….

But what I have shown should keep up busy for a while.

Thank you.