Aquecimento global: mais águas-vivas.

Figura original aqui.

O aquecimento global está mudando a face da Terra e dos oceanos. Efeitos no clima nós já sentimos faz tempo: chuvas exageradas em certas regiões, falta de água em outras, chuvas fora de época (ex: hoje choveu em Fortaleza, o que é pouco comum para o mês de julho), ondas de calor ou frio, derretimento de geleiras em muitas regiões. Em resumo, vivemos em mundo com o clima mais extremo.

Esses eventos climáticos afeta todos os ecossistemas. Algumas espécies podem desaparecer pelo simples fato da temperatura aumentar 1 ou 2 graus centígrados (ex: sapos, rãs, corais). Outras podem se propagar para novos ambientes. Um exemplo: corremos o risco de mais acidentes com águas-vivas. Ver notícia aqui.

Para saber mais: Increasing jellyfish populations: trends in Large Marine Ecosystems, por Lucas Brotz, William W. L. Cheung, Kristin Kleisner, Evgeny Pakhomov e Daniel Pauly. Link desse artigo aqui.

Abstract: Although there are various indications and claims that jellyfish (i.e., scyphozoans, cubozoans, most hydrozoans, ctenophores, and salps) have been increasing at a global scale in recent decades, a rigorous demonstration of this has never been presented. Because this is mainly due to scarcity of quantitative time series of jellyfish abundance from scientific surveys, we attempt to complement such data with non-conventional information from other sources. This was accomplished using the analytical framework of fuzzy logic, which allows the combination of information with variable degrees of cardinality, reliability, and temporal and spatial coverage. Data were aggregated and analyzed at the scale of Large Marine Ecosystem (LME). Of the 66 LMEs defined thus far that cover the world’s coastal waters and seas, trends of jellyfish abundance after 1950 (increasing, decreasing, or stable/variable) were identified for 45, with variable degrees of confidence. Of those 45 LMEs, the majority (28 or 62%) showed increasing trends. These changes are discussed in the context of possible sources of bias and uncertainty, along with previously proposed hypotheses to explain increases in jellyfish.