Assessment Summary

The summary table presents our expert opinion on a single comparable assessment of status and trend across all components assessed for healthy and biologically diverse seas (please note no assessment has been made for microbes or turtles). We have done this by assigning a single colour for status where: green indicates few or no problems, amber indicates some problems and red indicates many problems. Trend arrows are also provided based on the evidence available, showing whether the state or condition of the component is improving , remaining stable or deteriorating .

Details of the reference conditions and baselines against which state is assessed for each component can be found in the Feeder Report prepared by the Healthy and Biologically Diverse Seas Evidence Group, along with the time period over which the trend is measured. The confidence rating of each assessment is also estimated in the Feeder Report, based on criteria developed by the Marine Climate Change Impacts Partnership (MCCIP). Assessments which have been made with low confidence are indicated in the summary table.

A more detailed discussion of the rationale for this approach, ‘traffic-light’ status, and the confidence assessment is given in Chapter 1. The ‘traffic light’ status assigned originates from the detailed assessments made for each component in the Feeder Report. Each component assessment section in the Feeder Report was accompanied by a table which summarised the findings if sufficient evidence was available. It is important to note that other than the six broad habitat assessments, the status assessments here are additional to those included in the Feeder Report chapters. The Feeder Report chapters focus on assessments of state, trend, pressures and impacts, with this varying between chapters depending on the information that was available.

The Feeder Report assessments provide valuable additional information that can be used to give context to the summary assessments in the summary table presented here and provide a greater understanding of each component, its status and the pressures to which it is subject.

Summary Tables

Habitats

Components currently assessed	Region
Intertidal rock	Regions 4 & 5 are already affected by rising sea levels and by rising air and water temperatures. This has lead to changes to rocky shore communities. Localised shellfish harvesting is a pressure in some Regions as is the presence of non-native species. Intertidal rock found at Rockall Island in Region 8.
Intertidal sediments	Main pressures are historical land claim and the presence of coastal structures, non-native species and beach litter; the extent of these pressures varies considerably around the coast. Rising sea level is also resulting in loss of intertidal sediments in some locations
Subtidal rock	Sub-tidal rocky habitats are generally only subject to local pressures such as construction/maintenance of coastal infrastructure (e.g. large ports), and bottom trawling
Shallow subtidal sediments	All Regions are affected to varying degrees by fish dredges and trawls. Smaller fishing vessels tend to fish these shallow habitats so the extent of their activities is less certain than for larger vessels. Other local pressures include occurrence of non-native species, aggregate extraction and pollution
Shelf subtidal sediments	All Regions are affected to varying degrees by dredging and trawling by large fishing vessels. Their movements are generally better known and understood. Region 3 experienced less fishing than other Regions. Other local pressures include occurrence of non-native species and renewable infrastructure
Deep-sea habitats	Region 7 deep sea habitats are affected by bottom trawling and litter such as discarded nets which damage vulnerable cold-water coral communities

Species

Components currently assessed	Region
Plankton	Plankton communities are not generally subjected to anthropogenic pressures. Significant changes in species have been recorded as a result of rising temperatures, which can have knock-on effects on foodwebs and marine ecosystems
Bottom-living marine fish	Status has improved since the 1980s due to recent reductions in fishing effort although communities are still thought to have deteriorated with respect to historical conditions. The main pressures are removal of fish through commercial fishing activities and changes to species distribution and composition as a result of changes in water temperature that are a result of the changing climate
Commercial fish stocks	Based on the assessment in Chapter 5 (Productive Seas), fishing mortality has declined significantly in many of the assessed fish stocks in UK waters and although there is some way to go before the majority of commercial stocks are considered to be exploited at safe levels, there have been marked improvements. The main pressure is removal of fish through commercial fishing activities. However, for some stocks the change in water temperature is thought to be a contributing factor
Estuarine fish	The lack of data available for estuarine fish makes any conclusions tentative. What evidence there is suggests an overall increase in diversity and number of fish linked to cleaner estuaries but with a significant reduction in eel recruitment reflecting an Atlantic-wide trend. Although estuarine communities have improved in some Regions, the recent decline in eels (and salmon) often reduces the overall score
Harbour seals	Harbour seals have been decreasing in abundance, dramatically in some areas (up to 50%), particularly in Regions 1, 2 & 7. Although subjected to various pressures (competition with grey seals, predation by killer whales, unregulated shooting, and declines in important prey species such as sand eels) the reason for this decline is still unknown
Grey seals	Although grey seals are generally not experiencing any problems, populations in Regions 4, 5 & 6 are no longer increasing. The reasons for this apparent plateau in the population are not clear at present
Cetaceans	Historic by-catch is suspected to be responsible for low numbers of cetaceans in the Eastern Channel (Region 3) but more data are required to confirm the cause. Impact of persistent contaminants is decreasing
Seabirds	There have been substantial declines in seabird abundance in north and north-west Scotland where the main pressures are climate change and the introduction of non-indigenous species (e.g. rat and mink affecting nesting sites). Tern numbers breeding in the Eastern Channel have declined due to natural causes (i.e. predation and storm events)
Waterbirds	Waterbirds are generally not experiencing any problems and their status has been improving since the mid-1970s. An exception is Region 5 where waterbird populations are moving east, away from traditional sites; the reasons for this change are unknown but may be due to climate change