Ten Years of Induced Ocean Warming Causes Comprehensive Changes in Marine Benthic Communities

Abstract

One of the most commonly predicted effects of global ocean warming on marine communities is a poleward shift in the distributional boundaries of species with an associated replacement of cold‐water species by warm‐water species. However, these types of predictions are imprecise and based largely on broad correlations in uncontrolled studies that examine changes in the distribution or abundances of species in relation to seawater temperature. Our study used an 18‐year sampling program in intertidal and subtidal habitats and before–after, control–impact analyses. We show that a 3.5°C rise in seawater temperature, induced by the thermal outfall of a power‐generating station, over 10 years along 2 km of rocky coastline in California resulted in significant community‐wide changes in 150 species of algae and invertebrates relative to adjacent control areas experiencing natural temperatures. Contrary to predictions based on current biogeographic models, there was no trend toward warmer‐water species with southern geographic affinities replacing colder‐water species with northern affinities. Instead, the communities were greatly altered in apparently cascading responses to changes in abundance of several key taxa, particularly habitat‐forming subtidal kelps and intertidal foliose red algae. Many temperature‐sensitive algae decreased greatly in abundance, whereas many invertebrate grazers increased. The responses of these benthic communities to ocean warming were mostly unpredicted and strongly coupled to direct effects of temperature on key taxa and indirect effects operating through ecological interactions.

Climate driven changes in subtidal kelp forest communities in NW Spain

“…This most likely indicates a decrease in suitable habitat (kelp) during that period, as already proposed by the descriptions of the professional divers. Climate change is affecting marine communities in numerous ways; however it has been argued that its indirect effect by the loss of habitat forming organisms is of even greater concern (Schiel et al, 2004). In this study we also showed an increase in decapod landing from 2010.…”

“…Kelp acts as both substratum for many sessile animals and algae and as habitat for mobile organisms living in and feeding directly on the kelp or their associated species (Duggins, 1980;Christie et al, 2009). A decline in habitat-forming subtidal kelp unsurprisingly results in major changes in near shore community composition (Schiel et al, 2004;Wernberg et al, 2012).…”

Evidence for a General Species–time–area Relationship

“…The intertidal algae and invertebrate datasets were collected at 3 sites along the central California coast (Schiel et al 2004). Each site has two 30 m transects at different tidal elevations (+0.3 m and +0.9 m mean lower low water).…”

Crónica de un conflicto anunciado: Tres centrales termoeléctricas a carbón en un hotspot de biodiversidad de importancia mundial

“…En el caso de termoeléctricas costeras, el agua es obtenida del mar, lo que implica que grandes cantidades de organismos planctónicos son sometidos a rápidos incrementos de temperatura y presión, daños mecánicos por abrasión y efecto de biocidas antiincrustantes, provocando impactos negativos sobre su abundancia, composición y sobrevivencia (Bamber & Seaby 2004, Taylor 2006. Posteriormente, el agua utilizada es descargada con una temperatura incrementada en 6 a 10 ºC respecto a la temperatura ambiente (Poornima et al 2006), pudiendo alterar localmente la estructura comunitaria del plancton (Poornima et al 2006, Jiang et al 2009), bentos (Schiel et al 2004) y peces (Teixeira et al 2009). Si sumamos otros factores de calentamiento de las aguas (e.g., El Niño), la tolerancia térmica de muchas especies puede ser sobrepasada (Zargar & Ghosh 2007).…”