Monitoring Razor Clams as an Indicator of Nearshore Ecosystem Health

Brown bears often eat razor clams, like this one in Katmai National Park and Preserve.

Razor clams live embedded in the sand along the intertidal beaches and in subtidal areas. They are a source of food for bears, sea otters, other marine mammals, and people. Bivalves, such as clams and mussels, are used in environmental monitoring to better understand the local conditions and how they might be changing. Using molecular and genetic tests on bivalve physiology, scientists can detect the effects of environmental and anthropogenic stressors. For example, changes in tissue and shell growth can be linked to increased temperature, pollution, ocean acidification, and changing nutrients in the ocean waters.

This study looked at Pacific razor clams in Lake Clark and Katmai national parks and preserves to see if they were physiologically similar and may be good indicators to monitor the health of nearshore marine ecosystems. While some differences were detected between the sites in the two parks, these differences pointed to how nearshore environments differ and can be a baseline against which future changes can be measured. Long-term monitoring of razor clams will improve our ability to detect changing environmental conditions and inform decisions about fisheries management.

Monitoring nearshore ecosystem health using Pacific razor clams (Siliqua patula) as an indicator species

Abstract

An emerging approach to ecosystem monitoring involves the use of physiological biomarker analyses in combination with gene transcription assays. For the first time, we employed these tools to evaluate the Pacific razor clam (Siliqua patula), which is important both economically and ecologically, as a bioindicator species in the northeast Pacific. Our objectives were to (1) develop biomarker and gene transcription assays with which to monitor the health of the Pacific razor clam, (2) acquire baseline biomarker and gene transcription reference ranges for razor clams, (3) assess the relationship between physiological and gene transcription assays and (4) determine if site-level differences were present. Pacific razor clams were collected in July 2015 and 2016 at three sites within each of two national parks in southcentral Alaska. In addition to determining reference ranges, we found differences in biomarker assay and gene transcription results between parks and sites which indicate variation in both large-scale and local environmental conditions. Our intent is to employ these methods to evaluate Pacific razor clams as a bioindicator of nearshore ecosystem health. Links between the results of the biomarker and gene transcription assays were observed that support the applicability of both assays in ecosystem monitoring. However, we recognize the need for controlled studies to examine the range of responses in physiology and gene transcripts to different stressors.

Bowen, L., K. L.Counihan, B. Ballachey, H. A. Coletti, T. Hollmen, B. Pister, and T. L. Wilson. 2020. Monitoring nearshore ecosystem health using Pacific razor clams (Siliqua patula) as an indicator species. PeerJ 8:e8761