The purpose of this study is to find out more about the habits and types of striped bass that visit or inhabit southern Maine’s Saco River estuary and Saco Bay.

• Are these fish a single group that migrates up and down the coast, stopping off at Saco Bay as part of their migratory journey?
• Or are there various groups of fish with different habits – some that live in the Saco River or Saco River estuary year-round and others that visit the area seasonally as a stopover during their annual migrations?

Knowledge of the extent and timing of migrations is necessary to accurately assess the abundance and range of individual species.

This information will, in turn, provide policy makers with better information to make certain that this important fish species continues to thrive in a manner that both preserves economics of Maine’s fisheries and the health of the coastal ecosystem.

The purpose of the University of New England striped bass study is to find out more about the habits and types of striped bass that visit or inhabit southern Maine's Saco River estuary and Saco Bay.

Considerations and Other Objectives

Striped bass are especially amenable to the use of individually coded acoustic tags because large juvenile- and adult-tagged individuals of both sexes may be reliably intercepted by fixed listening posts at strategic locations relative to the detection range of hydrophones.

These coastal migrant fishes are often constrained to narrow inlets upon entering the Maine coastal estuaries; also, estuary and river-resident striped bass are always constrained at least to the width of the river or bay and often at the narrowest points.

We are tagging striped bass with the most recently developed acoustic tags, and we are developing this application towards the potential integration with a growing network of hydrophones.

Saco River

The Saco River estuary is an excellent site for such a project for several reasons:

• The seasonal movement of adult and juvenile striped bass in this river has been well documented by the recreational fishery; those reports provide a solid context for the proposed work but lack potentially important information on fine-scale estuarine use.
• The geomorphology of the Saco River estuary is under study by the Army Corp of Engineers and geological oceanographers, thus allowing for integration of river physical data with striped bass migration patterns.
• The Saco River warrants special interest among recreational fishermen as an important hub of striped bass activity in southern Maine and thus among potential collaborators.
• The large population of striped bass in the study area makes tagging of large individuals quite convenient.
• Finally, fish from the area have been tagged with conventional external tags in past years under a program managed by the Coastal Conservation Association. In the future, expansion of our research program and collaboration with other institutions will greatly increase the number of fish tagged in the Saco River area. This will greatly expand the applicability of tags, in that data may be collected elsewhere (particularly in complementary studies of striped bass in the Kennebec River and Mid-Coast region), and of the hydrophones, in that movements of tagged fish from other studies will be recorded.

Applying Telemetry Technology

This study will be significant in that it will be a crucial first step at applying telemetry technology to determine migration dynamics of striped bass in the Saco River and adjacent coastal waters of the Gulf of Maine.

The proposed study will be an important advance for two reasons:

• The migratory stock structure of striped bass in the Gulf of Maine may have changed considerably in just the last decade owing to an incredible resurgence in the number of striped bass spawned in the Chesapeake Bay and Hudson River, and with long-term changes in climate that may alter the participation of other stocks in coastal migration.
• The use of telemetry allows us, for the first time, to address questions of fidelity and cycle variation among migrants, and the division of co-occurring fishes into reproductively isolated contingents. The identification of contingents in other research studies has been demonstrated to be essential to the successful management of other estuarine species such as weakfish, Cynoscion regalis. In addition to the implications that stock definition based on habitat use will have to fisheries managers, this knowledge is critical to the identification of essential fish habitat.