Effects of climate change on Mediterranean marine ecosystems: the case of the Catalan Sea

Abstract

The Catalan Sea, located between the eastern Iberian coast and the Balearic Islands, is a representative portion of the western Mediterranean basin and provides a valuable case study for climate change effects on Mediterranean ecosystems. Global warming is reflected regionally by a rise in sea level over the last century, an increase in surface temperature of around 1.1°C in the last 35 yr, a progressive salinisation of intermediate and deep waters and a strengthening of the stratification. A likely scenario of what we can expect in the Mediterranean Sea is a considerable decrease in rainfall and wind, warmer surface waters and a prolonged stratification period. The effects on Mediterranean ecosystems are evident in: (1) a meridionalisation of the algal, invertebrate and vertebrate species, which favours the more thermophilic species over the temperate species; (2) mass mortality events of sessile invertebrates of the coralligenous communities owing to anomalous warm waters during the period when food is scarce; (3) increases in the smallest phytoplankton due to the prolongation of the water stratification period; (4) proliferation of gelatinous carnivores, including jellyfish, due to the temperature rise and the lack of rainfall; (5) a faster acidification of seawater, compared with the global oceans, accompanied by a decrease in the capacity to absorb atmospheric CO 2 . In order to anticipate and mitigate these predicted changes, we recommend investing in research and observation, conserving areas that serve as indicators of climate change and reducing other anthropogenic pressures such as habitat destruction, overfishing or pollution, which may act synergistically to accelerate these changes.

Intra-Specific Variation Reveals Potential for Adaptation to Ocean Acidification in a Cold-Water Coral from the Gulf of Mexico

“…It has been previously stated that ecosystems in the Mediterranean Sea are likely to show the first signs of ocean acidification (Calvo et al, 2011), but our results coupled with previous work (Lunden et al, 2014a;Georgian et al, 2016b) suggest that the deep-water coral ecosystems of the Gulf of Mexico are also extremely vulnerable. Reductions in calcification rate and increased dissolution of standing dead skeleton would cause instability and degradation of the deep reef structures, which would lead to biodiversity loss and cascading effects throughout the larger Gulf of Mexico ecosystem.…”

Salinity-induced activation of the myo-inositol biosynthesis pathway in tilapia gill epithelium

“…Euryhaline fish tolerate large changes in salinity and the mechanisms underlying such tolerance are of interest in the context of global salinization and warming (Calvo et al, 2011;Somero, 2012). One of the few organs of euryhaline fish that is directly exposed to the external environment is the gill, and gill epithelial cells are exposed to significant osmotic stress during changes in habitat salinity.…”

A comparison of remote-sensing SST and in situ seawater temperature in near-shore habitats in the western Mediterranean Sea

“…However, despite the regularity of the seasonal cycle, the Mediterranean Sea is among the most rapidly warming areas of the global ocean (HoeghGuldberg et al 2014), with concomitant severe impacts on its biota (Calvo et al 2011, Marbà et al 2015. Over the last 2 decades, mass mortality events directly or indirectly linked to elevated summer ST have affected benthic organisms such as gorgonians , Garrabou et al 2009), sponges (Maldonado et al 2010, Cebrian et al 2011) and aquacultured bivalve molluscs (Gazeau et al 2014).…”