Abstracts Category : Other

Benthic community mapping in the northern Dreki area, Iceland

by Tadhunter 1991 Jessica

The deep Arctic seafloor supports a wide diversity of benthic megafauna that provide important ecosystem services. However, deep-sea Arctic environments are increasingly under threat due to climate change and ocean acidification as well as the ongoing expansion of human activities such as fishing, shipping, and hydrocarbon production into deeper and higher-latitude waters. There is thus a growing need for baseline information on megafauna community composition and distribution, without which assessment of impacts is virtually impossible. This study reviewed the available information on deep-sea megafauna communities in the Greenland-Iceland-Norwegian (GIN) Seas. An in-depth review of 12 studies documented a diverse array of benthic communities and revealed large regional variations in the quantity and quality of information. No information was available for the northern Dreki area in the Icelandic EEZ despite interest in hydrocarbon exploration in this area. This study modelled the distribution of communities at a 10,500 km2 study site located within the northern Dreki area. Acoustic and benthic surveys were carried out at this site in 2008. The benthic data were analysed using multivariate methods, resulting in the identification of five megafauna communities. Random forest was used to model the relationship between communities and variables derived from the acoustic survey data, including depth and backscatter, which enabled the generation of a full-coverage map of predicted community distribution. While this map indicates that the impacts of hydrocarbon operations could greatly alter community structure in the northern Dreki area, further studies using more comprehensive datasets are required to confirm these findings. Hafsbotninn norlgum hafsvum einkennist af fjlskrugu lfrki strvaxinna botndra. En essi norlgu svi eru undir auknu lagi af vldum hnattrnnar hlnunar og srnun sjvar, sem og auknum athfnum mannsins, svo sem af vldum veia, skipaflutninga og oluvinnslu, oft miklu dpi. ljsi essa er v rk nausyn a afla grunngagna um samflagsgerir botndra og tbreislu eirra, en n slkra gagna er mgulegt a meta hrif af vldum mannsins lfrki hafsbotnsins. essari rannskn voru teknar saman birtar upplsingar um djpsjvarbotndr og samflg sem finnast grnlenska, slenska og norska hafsvinu. etta yfirlit byggi upplsingum r 12 greinum, sem sndi a essu svi vri fjlskrugt dralf en jafnfram a a vri mikill svisbundinn breytileiki magni og gum gagnanna. ri 2008 var landslag hafsbotnsins sem og lfrki Drekasvinu kanna tveimur rannsknaleingrum Hafrannsknastofnunar. Ggn r essum leingrum voru notu hr essu verkefni til a kortleggja tbreislu botndrasamflaga Drekasvinu, innan svis sem er 10,500 km2. Me fjltta aferum voru annig skilgreind fimm samflg botndra svinu. Random forest lkani var beitt til a kanna sambnd milli margvslegra umhverfistta svo sem dpis og botnhrku og ess lfrkis sem