The Working Group on Ocean Hydrography (WGOH) identify several key trendsacross the North Atlantic in its annual report – both ocean conditions in 2017 and atmospheric conditions over the winter of 2016/2017.
One highlight in ocean conditions saw that across most of the North Atlantic region, sea surface temperature was higher than usual, except from the central subpolar North Atlantic and the Baltic Sea. In the central subpolar North Atlantic, a cold anomaly observed in the surface and upper ocean for the past four years weakened and shifted northwestward into the Irminger Sea.
The North Atlantic Oscillation (NAO) index is a measure of the difference in the atmospheric pressure at sea level between the Icelandic low, a centre of low pressure, and the Azores high, an area of high pressure. The index is a simple indicator of the strength of these two pressure systems and of the strength and direction of westerly winds and storm tracks across the North Atlantic that they help govern. The 2016/2017 index was positive (+1.47), meaning a stronger westerly wind system. This is the fourth consecutive winter that the index has been positive, the first such positive run since 1992-1995.
Many diadromous fish species have threatened status and suffer from environmental degradation and human-induced changes, especially in reproduction areas. The main threats to diadromous fish include migration barriers (e.g. dams), river construction, local inputs to rivers, lagoons, and estuaries (pollution, eutrophication, acidification), habitat loss, and overfishing.
CRR No.348 Data-limited diadromous species – review of European status updates the status and distribution of selected species that have completely or partially diadromous populations.
The report has been researched by the Working Group on Data-Limited Diadromous Species (WGDAM), a subgroup of ICES Working Group on the Science Requirements to Support Conservation, Restoration and Management of Diadromous Species (WGDIAD).
The group has identified biological knowledge gaps and key stressors of diadromous species and the report delivers fundamental information for further work on development of systematic monitoring and stock assessment of key diadromous species or species groups.
Read the full report online.
The focus of monitoring at sea has moved from researching one specific topic, such as hydrography, chlorophyll, or fish species, to a wider ecosystem scope, where multiple elements in the system, as well as their presumed relationships, are of importance.
CRR 347 Moving towards integrated ecosystem monitoring focuses on this shift and provides structured guidance on how to set up monitoring at sea.
The guidance takes a stepwise approach, highlighting the important points for consideration. The methodology has been developed by the participants of the Working Group on Integrating Surveys for the Ecosystem Approach (WGISUR).
Read the full report online.
ICES expert groups share their research through our publications. All our series, Cooperative Research Reports (CRRs), Techniques in Marine Environmental Sciences (TIMES), Identification Leaflets, Series of ICES Survey Protocols, and ICES Scientific Reports can be found in our library.