Effective design of a multispecies research program.
The first item in the development of any research program is to determine what information is needed to answer the questions you have. Below are some important questions to ask and the answers specific to our groups.
- What are we trying to accomplish?
- Determine absolute abundance\ adult population sizes for several important species.
- Quantify geographic and seasonal distributions. Where and when the fish are?
- Discover trophic interactions between species. Who eats who?
- Provides the data to build multispecies models and determine their feasibility.
- How will we fund the research?
- What gear will we need to do this? See ChesMMAP methods for more detail.
- A vessel capable of providing a sampling platform.
- A net that targets adult fin fish.
- A data collection system.
- A way to determine the efficiency of the gear. (Acoustics and net mensuration)
- Take water quality measurements. (YSI. HydroLab, Eureka Environmental)
- Scales to weigh fish.
- Measuring boards for length and girth.
- Dissection equipment to obtain ageing and gut samples.
- Preservation method and storage containers.
- How often should samples be collected and on what scale?
- Since we want to discover seasonal variations in distribution, sampling should include as many seasons as possible. In the Chesapeake Bay many species leave during the winter. Our sampling consists of a cruise every 2 months from March to November to maximize available funds to research potential.
- A large enough sample must be taken to minimize bias and maximize spatial coverage. We sample 90 stations in the bay every cruise.
- How will we analyze our data?
- Create a age lab that will age the otolith or vertebra samples collected and enter the details into the data base.
- Create a gut lab that will identify and quantify the gastric contents of all samples.
- Run analyses on length data and weights of each species.
- Determine the efficiency of the gear for extrapolation of the sample to the rest of the system.
- Validate the work.
Figure 4. Conceptual diagram depicting the interrelationships between scale, sampling platform, and data collection to be considered when developing a multispecies modeling-field program.
