Planting Trees

POPULATION ASSESSMENT

Population assessments, or stock assessments, are a tool to measure the abundance of a given population, and can improve fisheries stocks by maximizing harvest and minimizing the risk of overfishing (1). Certain parameters are included in a mathematical model that can provide an estimate of a species biomass in a given area. These parameters typically include estimates of removal (i.e. predation, fisheries harvest, natural mortality), life history data (i.e. growth rates, sexual maturity, recruitment success), and any other factors that can affect stock abundance year to year (1). Because stock assessments utilize a wide range of information, they can be the most reliable means to estimate the status of fisheries stocks (2)


Studying marine species can be difficult due to the difficulty in sampling large areas of the ocean, as well as the complex interactions between species and ocean variability (3). Because the construction of stock assessments requires multiple complex parameters, inaccurate assumptions of certain parameters, such as life expectancy, can ultimately lead to inaccuracy of the model (3,4). Among harvested species in the United States, the most commercially valued tend to be the most likely to be assessed due to the economic benefits of having accurate biomass estimates (5). Despite that Dungeness crab is the most highly valued single species fishery on the west coast of North America, there is no stock assessment for them in Washington waters. This lack of stock assessment is due to the lack of a high-quality and complete dataset that is required to construct an accurate model that encompasses all life history stages (Table XX) (1)


Cooperative research groups can play a critical role in advancing fisheries management and population assessments by improving the spatial, temporal, and categorical qualities of data collection that can be missed when organizations acting unilaterally (6). Additionally, when groups work cooperatively together, the group is more likely to identify relevant scientific research that most adequately addresses pressing management needs (6). As such, the PCRG has worked and will continue to work together to fill research gaps that can contribute to the construction of a stock assessment for Dungeness crab in Washington waters.