Streaming Media
Presentation Abstract
Pacific herring play a critical role in the food web of the Salish Sea. Because they are not charismatic megafauna there has been a lack of attention on the species, resulting in a limited understanding of their population dynamics and downward trends in their populations. The Cherry Point stock, centered 30 miles north of Bellingham Bay, has declined roughly 97% since the 1970s. This massive decline is a point of concern for environmental and fishery managers and has led to research into both the initial decline and its lack of recovery. One key hypothesis in need of research is whether the Cherry Point stock is experiencing increased predation from the nearshore fish, bird, and invertebrate community due to its late spawn timing and spawning behavior. To that end, we investigated predation on spawn by deploying predator exclusion enclosures and remote underwater time lapse cameras at spawning locations of both the declining Cherry Point stock and a nearby stock with stable population trends, Semiahmoo Bay. This study aimed to understand (1) whether the impact of predation has a significant effect on egg survival on the Cherry Point spawn, (2) how predation differs between Cherry Point and Semiahmoo Bay, and (3) if fish, birds, and invertebrates of the nearshore community aggregate at spawning sites and utilize Pacific herring spawn as a pulse resource. Our initial work in 2021 showed that there are a variety of species that feed on Pacific herring eggs and the nearshore predator community changes with the presence of spawn. An additional field season in 2022 will address the lack of recovery at Cherry Point and the ecological interactions between Pacific Herring eggs and the nearshore community to understand the impact of a declining population.
Session Title
Salmon Management & Marine Survival
Conference Track
SSE4: Fish Science and Policy
Conference Name
Salish Sea Ecosystem Conference (2022 : Online)
Document Type
Event
SSEC Identifier
SSE-traditionals-286
Start Date
27-4-2022 9:45 AM
End Date
27-4-2022 11:15 AM
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Type
Text
Language
English
Impacts of Predation on Pacific Herring Egg Survival in the Southern Salish Sea
Pacific herring play a critical role in the food web of the Salish Sea. Because they are not charismatic megafauna there has been a lack of attention on the species, resulting in a limited understanding of their population dynamics and downward trends in their populations. The Cherry Point stock, centered 30 miles north of Bellingham Bay, has declined roughly 97% since the 1970s. This massive decline is a point of concern for environmental and fishery managers and has led to research into both the initial decline and its lack of recovery. One key hypothesis in need of research is whether the Cherry Point stock is experiencing increased predation from the nearshore fish, bird, and invertebrate community due to its late spawn timing and spawning behavior. To that end, we investigated predation on spawn by deploying predator exclusion enclosures and remote underwater time lapse cameras at spawning locations of both the declining Cherry Point stock and a nearby stock with stable population trends, Semiahmoo Bay. This study aimed to understand (1) whether the impact of predation has a significant effect on egg survival on the Cherry Point spawn, (2) how predation differs between Cherry Point and Semiahmoo Bay, and (3) if fish, birds, and invertebrates of the nearshore community aggregate at spawning sites and utilize Pacific herring spawn as a pulse resource. Our initial work in 2021 showed that there are a variety of species that feed on Pacific herring eggs and the nearshore predator community changes with the presence of spawn. An additional field season in 2022 will address the lack of recovery at Cherry Point and the ecological interactions between Pacific Herring eggs and the nearshore community to understand the impact of a declining population.
