5 research outputs found
Reconstructing long-term ecological data from annual census returns: a test for observer bias in counts of bird populations on Skokholm 1928–2002
Long-term ecological data are essential for conservation and to monitor and evaluate the effects of environmental change. Bird populations have been routinely assessed on islands off the British coast for many years and here long term data for one such island, Skokholm, is evaluated for robustness in the light of some 20 changes in observers (wardens) on the island over nearly eight decades. It was found that the dataset was robust when compared to bootstrap data with no species showing significant changes in abundance in years when wardens changed. It is concluded that the breeding bird populations on Skokholm and other British offshore islands are an important scientific resource and that protocols should be enacted to ensure the archiving of records, the continuance of data collection using standardised protocols into the future, and the recognition of such long-term data for science in terms of an appropriate conservation designation
The efficiency of regional ballast water exchange: Changes in phytoplankton abundance and diversity
Ballast water was sampled on 12 occasions before and after an exchange process carried out in regional seas in order to assess the efficiency of this type of ballast water management at reducing the abundance and diversity of phytoplankton. Although there was an overall reduction in the average abundance and number of taxa after exchange this was not consistent between tanks and voyages. On some occasions there were changes in species composition after exchange and, in some cases, there were increases in potentially harmful species after the exchange process. Factors such as the depth of the water during the exchange process, the season and the method of exchange influenced the efficacy of the exchange process. The variability in the results after exchange mean that this is unlikely to be a ballast water management method that would give consistent results and careful consideration would have to be given to the suitability of using this method in regional seas as a means of reducing the risk of introducing non-native species
Status of introductions of non-indigenous marine species to the North Atlantic and adjacent waters 2003–2007
Over the past few years, new records and reports of non-native species have provid- ed additional insight into the potential vectors and spread of introduced pathogens, plants, and animals. This five-year report brings together and summarizes the non- native species introductions reported in annual reports to the Working Group on Introductions and Transfers for the period 2003 – 2007. Not all countries reported eve- ry year, limiting the information on species distributions. Most of the observations are from coastal areas and embayments, and they range from marine waters to brack- ish and, occasionally, freshwater. One exception is an American report on a tunicate that has invaded a productive offshore area 200 nautical miles from shore, suggesting that greater effort needs to be made to determine the offshore distributions of species.
One goal of this report is to facilitate understanding of the species present in nearby countries that may disperse to neighbouring countries. The document is divided into five general sections: pathogens, phytoplankton, algae and plants, invertebrates, and fish. Rather than list each country alphabetically, each section reports on non-native species by region: Northeast Atlantic, Baltic, Mediterranean, Northwest Atlantic, Great Lakes, and northwest Pacific, and includes reports from Australia and New Zealand. This regional approach intends to provide insight into which species are spreading from country to country and how quickly they are dispersing. The sum- mary tables at the end of the sections also present species by taxon and by region. Species such as Crepidula fornicata, Eriocheir sinensis, and Crassostrea gigas have been present in their non-native areas for a long time, but if they were expanding their ranges, they were included in this report. A few reports provided lists of non-native species not previously reported to ICES, and these species are also included. The edi- tors have attempted to update taxonomic nomenclature, based on the World Register of Marine Species (WoRMS) and for algae also on www.algaebase.org