Changes in the marine ecosystems may occur with more species of warm and subtropical waters and less boreal species. There may be a reduction of marine productivity (1) and productive waters may shift to the north (2). The most vulnerable species will be the Mediterranean red coral and the Canary Isles black coral, the fields of algae and the fields of marine phanerogams (3).
Changes in the distribution of fish species associated with European tidal estuaries along the northeast Atlantic seaboard were studied by comparing the mean latitude of distributions according to fish survey data from the 1970s with data from 2004–2007. 55 tidal estuaries from Portugal to Scotland were studied. Among the 15 most common species, 11 displayed a positive difference between current and past mean latitudes suggesting a northward shift of the populations. These results indicate that a number of fish species associated to estuaries seem to have migrated northwards over the last 30 years, possibly due to water warming (5).
The Mediterranean Sea is warming in both shallow and deep waters (7). This warming is part of global climate trends and not a regional phenomenon (6). Fisheries landings fluctuations of the seven Mediterranean EU member states (Spain, France, Italy, Slovenia, Greece, Malta and Cyprus) during 1985-2008 were examined for the most abundant commercial species (59 species) and showed significant year-to-year correlations with temperature for nearly 60 % of the cases (6). From these, the majority (~70 %) were negatively related and showed a reduction of 44 % on average. Increasing trends were found, mainly in the landings of species with short life spans, which seem to have benefited from the increase in water temperature. These results indicate that climate should be examined together with fisheries as a factor shaping stock fluctuations (6). The reason why the landings of some species have increased or decreased with temperature oscillations may be related to stock spawning periods (6). An indirect effect of warming could also be related to food availability (potential modification of fish abundance by climate change through fluctuations in plankton abundance (8).
The economic impact of climate change on the sardine fishery in Portugal and Spain has been estimated for 2030 based on the predicted increase in the temperature of the Iberian-Atlantic waters (4).
The results show that as the sea surface temperature of the Iberian-Atlantic fishing-grounds rises, lower biomass and catch levels are obtained, and as a result, the economic yield also decreases. If the current trend in rising sea surface temperature remains the same (0.27°C per decade), the annual profits will decrease by 1.27% between now and 2030. For scenarios of 10% faster or 10% slower rise of the fishing ground temperature, the profits will fall by about 1.40% and 1.14%, respectively, on average for each year of the period analysed (4).
In absolute terms, the economic losses from the sea surface warming will be higher in the Portuguese regions than in the Spanish regions involved in the fishery, because the Portuguese catches represent over 70% of total landings in this fishery (4).
The references below are cited in full in a separate map 'References'. Please click here if you are looking for the full references for Spain.
- Government of Spain. Quinta Comunicación Nacional de España
- Comisión de Coordinación de Políticas de Cambio Climático (2007)
- Oficina Española de Cambio Climático (2008)
- Garza-Gil et al. (2011)
- Nicolas et al. (2011)
- Tzanatos et al. (2014)
- Vargas-Yáñez et al. (2008); Nykjaer (2009); Raitsos et al. (2010), all in: Tzanatos et al. (2014)
- Blanchard et al. (2012); Woodworth-Jefcoats et al. (2013), both in: Tzanatos et al. (2014)