Fantasy and folly in fisheries-dependent length sampling: a review of Trip Interview Program (TIP) Sampling protocols and its effect on stock assessme

Project: Research project

Description

In order to better understand how fisher behavior influences data collected from the fishing industry, a spatially explicit, agent-based bioeonomic model will be developed to represent some of the most important commercial reef fish species and the handline and longline fleets that harvest them in the Gulf of Mexico. This proposed project continues the work initiated by the PI and his collaborators, whom have developed a spatially explicit model for the West Florida shelf that incorporates the behavior of four reef fish species (red grouper, gag grouper, red snapper and mutton snapper) and two commercial fishing fleets (handline and longline) (Saul 2012). The new proposed model will extend the geographical scope of the current model to the entire U.S. shelf of the Gulf of Mexico. In doing so, biological parameters will be updated for all species in the model based on the most recent stock assessments for those species. In addition to the four species currently in the model, vermilion snapper, king mackerel, yellowedge grouper, and tilefish will be added. In addition to representing fish population biology and fisher behavior, the model will also include the sampling behaviors and decision-making of the government port agents who visit various fish houses and landing locations to measure the biological characteristics (i.e. length, age, gender, maturity) of a subset of the animals captured.
Together, the interacting dynamics of the fish populations, fishing fleets, and port agents will be used in the simulation to address several research questions. First, the model will be used to establish whether the behaviors and decision making of fishers in the Gulf of Mexico is playing a role in dictating the data that is collected and, if so, to what extent do fishery length, age, maturity, and abundance observations differ from system dynamics. Second, is the current dockside sampling protocol in place adequately capturing the composition (again length, age, maturity, etc.) of the removals being harvested from the Gulf? If not, how can the dockside sampling protocol, and thus the behaviors and decision making of the NOAA port agents, be modified to better capture a representative sample of the landings? Third, is dockside sampling adequately representative of the composition of the animals in the system across the entire stock? If not, is this due to the fact that sampling is not representative of the landings, due to the fact that fisher behavior dictates the spatial and temporal placement of observations, or both? If fisher behavior is having an effect on the timing and placement of fishery observations, then can fishery-independent efforts either be increased or redirected to fill spatial and temporal gaps where the fishing industry may not be adequately sampling. Finally, fourth, what are the implications of using uncorrected biased samples, either due to fisher behavior, dockside sampling protocol, or both, on stock assessment results and management advice? Can these biases be statistically corrected for in stock assessments?
StatusFinished
Effective start/end date2/1/171/31/18

Funding

  • DOC: National Oceanic Atmospheric Administration (NOAA): $14,678.00

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fishery
sampling
stock assessment
fish
fishing industry
decision making
reef
programme
protocol
effect
animal
biological characteristics
gender
gulf
simulation