Groundfishing Vessel Survey of Herring Spawning Grounds

Participants

Donald Perkins, Jr., Gulf of Maine Aquarium
Cameron McLellan, McFish Inc.
Philip O. Yund, Gulf of Maine Aquarium
Herring play a key role in New England's fishing economy. Robust stocks on Georges Bank offer a hopeful example of a fishery's potential to recover from commercial extinction. Yet the coastal spawning stock faces the majority of the fishing pressure and is thought to be in danger of depletion. Efforts to manage the coastal stock are hindered by the absence of independent information on abundance. Hydroacoustic survey techniques, which are widely employed in other countries, present a possible solution to this problem. The Gulf of Maine Aquarium Development Corporation (ADC) has recently tested an innovative, industry-based acoustic survey approach. Industry vessels have proven to be a cost-effective survey platform that may be superior to traditional research vessels for both shallow-water operations and the fish sampling that is a necessary component of acoustic surveys. Unfortunately, because of market pressure, commercial herring vessels can not devote sufficient time (circa 30 days) to survey the coastal stock during the narrow time window immediately prior to spawning.

Our solution is to utilize the acoustic survey capabilities of a ground-fish vessel (the F/V Adventurer). A scientific-grade echosounder and data logging system will allow that vessel to collect high-quality acoustic data. We will use a parallel transect design to survey pre-spawning herring aggregations along the Maine coast as they assemble from northeast to southwest during the autumn spawning season. Fish samples will be collected to determine species composition and permit accurate conversions between acoustic backscatter and herring biomass. We will also sample hydrographic variables that may be used to predict herring distributions (and hence more efficiently target future acoustic survey efforts).

We plan to complete the development of a cost-effective means of assessing and monitoring coastal spawning stocks of herring. The immediate measurable outcomes from this project will include: 1) the production of a biomass estimate for the coastal spawning stock, 2) the development of a standardized survey protocol for future years, and 3) analysis of possible correlations between herring distributions and oceanographic variables. However, the longer-term objectives of this program (to continue this program as a regular monitoring effort and incorporate the results into future stock assessment procedures) extend well beyond the project year.


Last modified: October 13, 2000