ABSTRACT
Manifestations of climate change in the Arctic include an increase in water temperatures and massive loss of sea ice enabling more light penetration. Yet to understand tempo and scale of these parameters change over time, constant monitoring is needed. We present 16-yr long-term datasets of sea water temperature and relative light intensity at two depth strata (8 and 14 ± 1 m) of two hard-bottom sites in southern Isfjorden proper (Spitsbergen, 78°N). The high temporal resolution of the datasets (every 30 min, between 2006-2022) makes them suitable for studying changes at a local scale, correlating environmental variability with observed processes in benthic assemblages, and serving as ground-truth for comparison with, for example, remotely sensed or mooring data. These datasets serve as baseline for long-term investigations in the shallows of a high-Arctic fjord undergoing severe environmental changes.
ABSTRACT
This study provided new data on shell mineralogy in 23 Arctic bivalve species. The majority of examined species had purely aragonitic shells. Furthermore, we measured concentrations of Al, Ba, Ca, Fe, K, Mg, Mn, Na, P, S, Sr and Zn in 542 shells representing 25 Arctic bivalve species. Species-related differences in concentrations of specific elements were significant and occurred regardless of locations and water depths. This observation implies the dominance of biological processes regulating elemental uptake into the skeleton over factors related to the variability of abiotic environmental conditions. Analysis of the present study and literature data revealed that the highest concentrations of metals were observed in bivalves collected in the temperate zone, with intermediate levels in the tropics and the lowest levels in polar regions. This trend was ascribed mainly to the presence of higher anthropogenic pressure at temperate latitudes being a potential source of human-mediated metal pollution.
