Energy Transfer to Upper Trophic Levels on a Small Offshore Bank
Abstract
We propose to combine field observations and laboratory experiments to understand the coupling of physical and biological processes that transfer energy from lower to higher trophic levels on a small offshore bank. We focus this study on Platts Bank, in the western Gulf of Maine, and on the relationship between internal waves, patchiness of planktonic organisms (especially euphausiids, Meganyctiphanes norvegica), and feeding and residence times of upper trophic level predators (marine and avian, but especially baleen whales, and particularly the abundant humpback whales, Megaptera novaeangliae). Observations from Platts Bank and other feeding hotspots in the Gulf of Maine show that they are ephemeral - sometimes very active, often not. Our goals are to understand the factors that drive the "on" and "off" patterns of feeding at features such as Platts Bank, and to gain insights into the foraging strategies and mechanisms employed by highly mobile predators to exploit ephemeral and scattered feeding locations. 1. Quantify patterns of upper trophic level use of Platts Bank over multiple years, extending observations from the original two years of observation that preceded this award. 2. Describe behaviors adapted to feeding on Platts Bank and foraging on networks of scattered feeding sites such as Platts. 3. Measure and describe the internal wave field, associated velocities, and euphausiid distribution and abundance patterns. 4. Use field and laboratory studies to document and quantify the behavior of euphausiids and the coupled bio-physical processes that affect surface patch formation, in particular testing the hypothesis that internal waves help drive surface aggregations and upper trophic level feeding.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2008
- Accession Number
- ADA505245
Entities
People
- David Fields
- Lewis S. Incze
- Scott D. Kraus
Organizations
- University of Southern Maine