Projects

Red snapper data collection, spatial modeling and population assessment in Northern Gulf of Mexico

End Date: 12/5/16

Objectives

  • To develop an Experimental Design using an operations management approach to plan the generation of a robust abundance estimate for red snapper. Below are our objectives for estimating abundance for red snapper in natural habitats, artificial reefs and oil and gas platforms. 
  • Collect catch, effort, and size composition data for red snapper on commercial and recreational vessels in the U.S. Gulf of Mexico from Florida through to Texas for one year (project duration is two years).
  • Map water column and benthic habitats over the study area for use with habitat suitability models (HSM). 
  • Develop habitat suitability models that relate catch rates (CPUEs) to environmental conditions.
  • Link the HSM to the habitat grids and create grids of abundance (CPUEs) using GIS.
  • Derive seasonal estimates of population numbers for juvenile and adult red snapper from the abundance grids.

Methodology

Additional PIs: Chris Jenkins, University of Colorado at Boulder and David Fries, Florida Institute for Human & Machine Cognition

Fishery Monitoring
Accurate georeferenced information is needed concerning catch, effort, and the size composition of red snapper caught in the U.S. Gulf of Mexico to support fisheries management. The main goals of the project are for observers and fishers to gather length frequencies, catch, and effort along with environmental data (bottom depth and bottom temperature) on commercial fishing vessels and anglers to record catch, effort on recreational vessels. A relational database will be created and used on recreational headboats and commercial bandit rig, hook and line, and longline fishing vessels tied to an electronic logbook (ELB).  Electronic monitoring devices (fish measuring boards, balances, and temperature-depth data loggers) will wirelessly transmit data to the ELB database in the wheelhouse. Recreational fisheries data will be collected by index fishermen using a cell phone application. The commercial and recreational data collected will be transmitted to shore daily using satellite communication systems. 

Habitat Mapping
Bottom types and bathymetry will be mapped using a sonar system linked to P-Sea WindPlot. Circulation modeling will produce seasonally averaged bottom temperature, salinity, and water current patterns. Seasonal maps will be created depicting habitats and zones of abundance of juvenile and adult red snapper.  Bottom types will be verified and densities per unit area of red snapper determined at fishing locations by lowering and retrieving a camera that scans 360 degrees. 

Habitat Suitability Modeling
Statistically rigorous habitat suitability models (HSM) will be developed to relate catch rates (CPUEs) across environmental gradients to mapped habitats. The study will determine length/age frequency distributions of red snapper and determine their spatial distributions over four seasons by length ranges representing juveniles and adults. Seasonal grids of abundance (CPUEs) will be created from which seasonal estimates of population numbers of red snapper will be derived.  

Rationale

The present document describes how we plan to analyze red snapper abundance data in relation to natural habitats, artificial reefs and oil and gas platforms. The data  will be used with HSM to predict population numbers of red snapper across the U.S. Gulf of Mexico. We are interested in collaborating with other groups involved in the study to integrate all the available data into the models.

 
Given that the area of interest is large, habitats vary, many social—economic and political regions are included, and expertise and resources are scattered across the region, and operations management approach is needed.  By operations management we are referring to planning, organizing, and coordinating in the context of producing a desired outcome: a robust abundance estimate for red snapper.  All of the components of the Gulf of Mexico system need to be coordinated in a cost-effective manner to provide the population estimates required, which can potentially contribute to a long-term monitoring and assessment program for red snapper in the Gulf of Mexico.  

Our intention is the following:

  1. Collaborate to build a data collection system that works toward the primary goal of building a robust estimate for the distribution and abundance of red snapper in the U.S. Gulf of Mexico.
  2. To increase cost-effectiveness by integrating methods that support electronic monitoring and reporting that complements other data collection approaches including fishery dependent monitoring, fishery observer, and catch/effort monitoring programs.
  3. To increase stakeholder buy-in by engaging the commercial and recreational fishing communities to expand our sampling and monitoring capacities and identify the best methods for doing so.
  4. To work under the expectation that all or parts of the methods incorporated in the experimental design plan might contribute to a long-term red snapper management strategy.

Results

Final experimental design report