Monitoring of outer Oslofjord 2014-2018. Benthos Surveys in 2014. Technical report

Summary

Benthic investigations included in 2014 surveys of soft bottom by SPI-sampling (Sediment Profile Imaging) and registrations of littoral communities by snorkeling. It was in August 2014 taken SPI images (Sediment Profile Imaging) of soft bottom at 29 stations in the outer Oslofjord. Most of the stations had a good condition (condition class 2), but three stations in the Hvaler area, as well as two new stations in Eksefjorden and Melbyfjord showed reduced conditions. It was undertaken frame registrations of littoral communities at 16 stations in 2014. For most stations results show little degree of impact from nutrients. Generally there has been a decline in the number of registered taxa from 2007 to 2014 at Station G3 at Horten and G17 south of Moss, while at the G15 at Kambo and G20 at Hankø has been a relatively steady increase. At several of the stations there was a marked presence of the alien species Pacific oysters.