Document Type

Thesis

Publication Date

12-12-2024

Keywords

Surf smelt, Forage fish, Diatoms, Toxins, Polyunsaturated aldehydes, Oxylipins, Salish Sea, Fish, Embryonic fish, Larval fish, Ocean, Phytoplankton, Food web, Fish life stages, Marine ecology, Fish ecology, Coastal ecosystem, Morphology

Abstract

Surf smelt (Hypomesus pretiosus) is a type of forage fish native to the Salish Sea. They are important economically for commercial fishing and ecologically as prey for larger animals and as indicators of ecosystem health. They spawn and develop in shallow coastal environments in close proximity to diatoms, some of which release polyunsaturated aldehydes (PUAs) when broken down. PUAs have previously been shown to negatively affect the development and reproductive success of invertebrates such as copepods, but it is unclear how PUAs affect vertebrate development. The purpose of this study was to test the physiological and morphological effects of increased PUA concentrations on forage fish, specifically surf smelt, in their embryonic and larval stages. To test this, surf smelt were exposed to different concentrations of PUAs in a laboratory experiment. Embryo mortality rates, larval body length, eye size, and otic capsules (sound sensory organs located on the head) were measured. Embryos had increased mortality rates when exposed to high concentrations of PUAs, and larvae had decreased body length and eye size. Other morphological and physiological measurements were taken that produced significant results, but those results are discussed in a separate study. These findings appear to support the hypothesis that increased PUA concentrations decrease embryonic and larval surf smelt fitness. The implications of this study suggest that increased PUA concentrations in the coastal Salish Sea environments could have detrimental effects on forage fish populations.

Comments

This paper is Joy Cobb's report for MACS 496: Communicating Marine Science, as part of Marine and Coastal Science, Western Washington University. Joy's advisor for writing this paper was Dr. Nina Whitney (the professor for MACS 496), and Joy's advisor for the research was Dr. Brady Olson.

Type

Text

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.

Language

English

Format

application/pdf

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