Spatially referenced stock assessment has only recently been attempted.
Currently, there is a growing interest in the development of marine GIS,
both to visualize these spatial data sets and to provide a platform for further
stock assessments and forecasting. As a result, a GIS incorporating
spatially referenced fisheries data and assessment models would contribute
significantly toward integrating this with other data sources and providing
quantitative and qualitative management advice, and therefore to
consequently improving integrated resources management.
Booth’s (1999, 2000b) studies correlated fishing effort with observed
age-structured fishing mortality to present a spatial perspective of the status
of the resource. Yield-per-recruit modeling was expanded in Maury and
Gascuel’s (1999) study providing insight into spatial problems inherent to
the delineation of marine protected areas and how these might affect fishing
operations. These models encapsulate three fundamental aspects to
fisheries modeling, all of which are spatiotemporally explicit: the environment,
the fish stock, and the fishing fleet.
Corsi et al. (2000) applied an equilibrium biomass production modeling
approach to assess the abundance of the Italian demersal resources as
a function of spatially distributed fishing effort. Peña et al. (2000) further
simplified the stock dynamics model and used a GIS to estimate the nominal
yield of jack mackerel (Carangidae) using fishing ground information,
and observed yield and sea surface temperature gradients. Using real-time
fishing catch and location data, together with near-real-time satellite imagery,
a transition probability matrix was used to calculate nominal yields at
various thermal gradients. A low-level GIS used by Cruz-Trinidad et al. (1997)
conducted a cost-return analysis of the trawl fishery of Brunei Darussalam,
south of the Philippines, where optimal fishing patterns were determined
using profitability indicators under various economic and operational scenarios.
Walden et al. (2000) also developed a simple, yet real-time, GIS for
the New England groundfish fisheries. This GIS evaluated various possible
fine-scale time-area closures to assess the projected mortality reductions
and losses in revenue of three principal demersal fish species: Atlantic cod
(Gadus morhua), haddock (Melanogrammus aeglefinus), and yellowtail flounder
(Pleuronectes ferrugineus).