Species composition and abundance of the shallow water fish community of Kongsfjorden, Svalbard

Abstract

Projections show that climate change will lead to structural change in Arctic ecosystems. Studies project the extinction of local species and intense species invasion to the Arctic Ocean. A lack of basic biological data about the Arctic shallow water fish community will make it hard to assess whether these communities will change or not. Baseline studies in combination with future reassessments are needed to establish a basic knowledge about the change of these communities. This study provides a quantitative first time description of the shallow water fish community of Kongsfjorden, Svalbard. The fish assemblage in the depth range from 3 to 12 m was determined with respect to abundance and species composition. Among a total sample size of 2804 specimens, the presence of 12 fish species and one family (Liparidae) was detected. Myoxocephalus scorpius (shorthorn sculpin) (74.9 %), Gadus morhua (Atlantic cod) (17.2 %), and Gymnocanthus tricuspis (Arctic staghorn sculpin) (3.8 %) were identified as the most abundant species across all sampling sites. A significant relationship between algal coverage and fish abundance was detected. Furthermore, we demonstrated a fjord inward increase in biodiversity along the south shore that might be correlated with a change in hydrographic regime.

Ecosystem Kongsfjorden: new views after more than a decade of research

“…Thus, baseline studies in combination with future reassessments are needed to establish basic knowledge about the change of these communities. A study by Brand and Fischer (2016) provided a quantitative first-time description of the shallow-water fish community in Kongsfjorden. Samples included 12 fish species, mainly shorthorn sculpin (Myoxocephalus scorpius) (74.9 %), Atlantic cod (Gadus morhua) (17.2 %) and Arctic staghorn sculpin (Gymnocanthus tricuspis) (3.8 %).…”

First year of practical experiences of the new Arctic AWIPEV-COSYNA cabled Underwater Observatory in Kongsfjorden, Spitsbergen

“…Although we detected Myoxocephalus scorpius during summer also on the stereoscopic images, the overall abundance remained quite low. Unfortunately, the fykenet catches of Brand and Fischer (2016), as with most other available marine studies of the fjord, are only available for the polar summer months, when our stereo-optical data revealed the lowest overall biota abundance at all. However, taking into account that fyke nets are highly time integrative and catch fish only directly at the bottom, the fyke-net and optical data may be complementary rather than contradictory.…”

“…For instance, comparing our stereo-optically assessed fish data with data from classical sampling devices in Kongsfjord (Brand and Fischer, 2016;Hop et al, 2002;Renaud et al, 2011) or even with sporadic diver observations (Brand and Fischer, 2016;Hop et al, 2002), it becomes clear that our optical sensors are also species selective. Brand and Fischer (2016) for example reported for the summer month a distinct occurrence of the benthic sculpin Myoxocephalus scorpius, a typical temperate and highly camouflaged benthic fish species in fykenet catches. Although we detected Myoxocephalus scorpius during summer also on the stereoscopic images, the overall abundance remained quite low.…”

“…However, taking into account that fyke nets are highly time integrative and catch fish only directly at the bottom, the fyke-net and optical data may be complementary rather than contradictory. In the study of Brand and Fischer (2016), fyke nets with a mesh size of 12 mm and a steering net of 18 mm were used. This type of net gear is highly selective for strictly benthic fish species with a high potential of entanglement, such as sculpins.…”

“…Parallel to this study, classic fishing campaigns were performed in 2012, 2013, and 2014 in the months June/July and September in the same area with standard fyke nets to provide ground-truth data for the remotely sampled fish data. These fishing data are published in Brand and Fischer (2016) for the years 2012 and 2013. The data for 2014 will be published together with a comparative analysis of the results of the UWO elsewhere (M. Brand, personal communication, 2016).…”