Changes in a Mid Atlantic estuary: trends and drivers of the fish and macroinvertebrate community in Delaware Bay
Date
2020
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Publisher
University of Delaware
Abstract
Cultures and economies around the world rely heavily on marine ecosystems. In order to effectively manage marine resources, we must understand the factors that drive marine community dynamics and productivity. The Delaware Bay, the third largest estuary in the United States, is a unique habitat with a diversity of fish and invertebrate species. The University of Delaware and the Delaware Department of Natural Resources Division of Fish and Wildlife have conducted a trawl survey in the Delaware Bay dating back to 1966 which takes place once a month at nine stations. The survey collects data on environmental conditions, species composition, number, weight, length, and sex of fishes and macroinvertebrates. Using the data from this trawl survey, we characterized the Delaware Bay marine community, both spatially and temporally, and explored long-term changes and associated environmental drivers of the fish and macroinvertebrate community in the Delaware Bay. We characterized three distinct biogeographic regions in the Bay described by environmental conditions and species assemblages. We found a significant increase in temperature and decrease in dissolved oxygen in the Delaware Bay over the course of the last three decades. In addition, the Delaware Bay marine community has experienced a significant increase in species richness due to community-wide reorganization, likely driven by ocean warming. Understanding how the marine community of Delaware Bay has changed through time, and how environmental conditions drive these changes, provides important insight into how climate change has impacted, and will continue to impact, the Delaware Bay ecosystem and similar estuarine ecosystems around the world. Our findings provide important baseline information necessary for effective implementation of ecosystem-based management.
Description
Keywords
Community ecology, Delaware Bay, Fish ecology