A recent scientific conference has provided new evidence for the effects of unseasonal summer storms on a variety of spectacular marine life, including deadly jellyfish, basking sharks and oceanic seabirds.

The third annual 'South West Marine Ecosystems' meeting, held in Plymouth in December 2009, brought together 40 representatives from the scientific, conservation, fishing and eco-tourism sectors. The aim was to discuss impacts of environmental change and conservation measures on marine life off southwest England.

A common theme was the influence of a third successive summer dominated by wet and windy weather, with southwest England particularly affected by a series of Atlantic storms. This led to an unprecedented mid-summer influx of the deadly Portuguese man-o-war jellyfish onto Cornish beaches, leading to temporary closure of some popular tourist hotspots such as Sennen Cove.

The stormy conditions also blew in record numbers of the Wilson's storm petrel, a tiny oceanic seabird that breeds in the southern Atlantic Ocean and is traditionally a very rare visitor to UK coasts. Several sightings of the spectacular black-browed albatross were also made during the summer and autumn, including the first in Cornwall for over 20 years.

Meeting organiser, Dr Russell Wynn of National Oceanography Centre, Southampton (NOCS) said: "The effect of these mid-summer storms on our marine life has been dramatic. If recent summers are an indication of future trends, then we might expect to see more exotic visitors around our coasts in the years to come."

However, the unsettled weather was bad news for basking sharks, which were only seen in very low numbers off southwest UK through the summer and autumn. During stormy conditions, their plankton prey is widely scattered, and it is believed that the sharks move further north and west in search of more productive waters at these times. In addition, the RSPB reported that the wet, cold conditions could be contributing to low productivity of breeding seabirds such as kittiwakes.

Helen Booker of RSPB said "Mid-summer storms are a particular problem for our breeding kittiwakes, which nest on exposed cliffs and headlands. The adult birds have difficulty finding food in very rough seas, while the chicks are vulnerable to chilling in persistently cold, damp conditions."

Conservation topics discussed at the meeting included a study on threatened seahorses in Studland Bay, Dorset, the establishment of a network of Marine Conservation Zones around our coasts, and ongoing efforts to reduce dolphin strandings and bycatch in southwest England.

South West Marine Ecosystems is an annual meeting that has run since 2007, and is organised by NOCS and the Sir Alister Hardy Foundation for Ocean Science (SAHFOS).

(ScienceDaily*, 05/01/2010)

*Adapted from materials provided by National Oceanography Centre, Southampton (UK), via EurekAlert!, a service of AAAS.