Abundance, biomass and caloric content of Chukchi Sea bivalves and association with Pacific walrus (Odobenus rosmarus divergens) relative density and distribution in the northeastern Chukchi Sea

Jordann K. Young, Bryan A. Black, Janet T. Clarke, Susan V. Schonberg, Kenneth H. Dunton

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

The northeastern Chukchi Sea is a shallow subarctic shelf ecosystem that supports a substantial benthic infaunal community of which bivalves are a major component. We assessed the patterns in population abundance, biomass, and caloric content of ten dominant bivalve taxa in relation to the distribution of the upper trophic level consumer Pacific walrus (Odobenus rosmarus divergens). Bivalves were collected over four cruises in the northeastern Chukchi Sea (2009, 2010, 2012, 2013). Our samples were largely dominated by calorie-dense, deposit-feeding species, including Macoma spp., Ennucula tenuis, Nuculana spp. and Yoldia spp. Weight-frequency distributions were strongly right-skewed for most taxa, though some showed evidence of a bimodal distribution. Caloric densities as measured through bomb calorimetry significantly differed among taxa (ANOVA F = 32.57, df = 9, p-value<0.001), and whole animal wet weight was found to be a reliable predictor of whole animal caloric content. Bivalve populations and peak caloric densities were centered on and to the southeast of Hanna Shoal, which coincided with peak Pacific walrus relative density (walruses per km surveyed) from July through October. Significant differences in mean caloric values were found between areas with and without walruses present (student's t-test, t=−2.9088, df = 252.24, p-value = 0.003952), as well as between areas with low and high walrus relative densities in the pooled annual dataset and in each individual month except October (ANOVA, p-value<0.05). The high-calorie deposit feeders that dominate these bivalve communities preferentially consume food sources, such as sea ice algae, that are likely to be affected by shifting sea ice dynamics. As such, continued warming has the potential to alter bivalve communities in the northeastern Chukchi Sea, which may have profound implications for upper trophic levels.

Original languageEnglish (US)
Pages (from-to)125-141
Number of pages17
JournalDeep-Sea Research Part II: Topical Studies in Oceanography
Volume144
DOIs
StatePublished - Oct 2017
Externally publishedYes

Keywords

  • Benthos
  • Biodiversity
  • Bivalve
  • Calorimetry
  • Chukchi Sea
  • GIS
  • Hanna Shoal
  • Marine mammals
  • Pacific walrus

ASJC Scopus subject areas

  • Oceanography

Fingerprint

Dive into the research topics of 'Abundance, biomass and caloric content of Chukchi Sea bivalves and association with Pacific walrus (Odobenus rosmarus divergens) relative density and distribution in the northeastern Chukchi Sea'. Together they form a unique fingerprint.

Cite this