‘Ecosystem canaries’ provide early warning signs of catastrophic changes to ecosystems

Read the full story from the University of Southampton.

New research, led by the University of Southampton, demonstrates that ‘ecosystem canaries’ can provide early warning signals of large, potentially catastrophic, changes or tipping points in ecosystems.

Like canaries that coal miners used to check for poisonous gasses deep underground, ‘ecosystem canaries’ species that are often the first to disappear from a stressed ecosystem. Their vanishing can be linked to changes in the functioning of ecosystems, which can serve as a warning that a tipping point is approaching.

Weathered Oil From Deepwater Horizon Oil Spill May Threaten Fish Embryos and Larvae Development

Read the full story from the Rosenstiel School of Marine and Atmospheric Science.

A research team led by scientists at the University of California, Riverside and the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science have found that ultraviolet light is changing the structure of the Deepwater Horizon (DWH) oil components into something more toxic, further threatening numerous commercially and ecologically important fishes. The DWH oil spill, in which more than three million barrels of crude oil got released in 2010 into the northern Gulf of Mexico, is the worst oil disaster in US history, contaminating the spawning habitats for many fishes.

“Ours is the first experiment evaluating the effects of DWH oil on the genetic responses of mahi-mahi embryos and larvae,” said Daniel Schlenk, a professor of aquatic ecotoxicology, who led the study published in Environmental Science and Technology.  “It is also the first experiment of this nature on a lifestage and species that was likely exposed to the oil.  We found that the weathering of oil had more significant changes in gene expression related to critical functions in the embryos and larvae than the un-weathered oil. Our results predict that there are multiple targets of oil for toxicity to this species at the embryonic life stage.”

Longest study of Great Lakes region birds finds populations holding steady

Read the full story from the National Forest Service.

A new USDA Forest Service report documenting an unprecedented effort to inventory birds in the western Great Lakes region and analyze changes in bird populations over the past quarter of a century found that across a trio of national forests, most birds are doing well in terms of both species diversity and population.

Survey of Intersex Occurrence in Largemouth Bass (Micropterus salmoides) from the Upper Illinois River Waterway

Mark W. Fritts, Jason A. Deboer , Andrea K. Fritts, Kristen A. Kellock, Robert B. Bringolf, Andrew F. Casper (2016). “Survey of Intersex Occurrence in Largemouth Bass (Micropterus salmoides) from the Upper Illinois River Waterway.” The American Midland Naturalist 176(1), 158-165. DOI: http://dx.doi.org/10.1674/0003-0031-176.1.158

Abstract: Intersex condition (ooctyes in testicular tissue) has been documented in many watersheds among a diverse variety of fishes worldwide. However, few studies have tested for the occurrence of the condition in fishes from rivers of the American Midwest. Midwestern watersheds, such as the Illinois River Waterway, U.S.A. may provide important new information about the effects of endocrine disrupting chemicals (EDCs) on fishes because of the variety of urban, industrial, and agricultural land uses within the watersheds. A first step in the study of EDCs in any ecosystem is a survey to document the symptoms of EDC exposure, such as intersex condition. Our objective was to test for intersex condition in male largemouth bass Micropterus salmoides in the lower Des Plaines River, an area directly affected by surface runoff and wastewater effluents from the Chicago Metropolitan Area. Histological analysis indicated that testicular oocytes were present in 21 of 51 (41%) largemouth bass sampled and oocyte numbers ranged from 1–25/thin section among intersex individuals. Our study details the severity of intersex in a population of largemouth bass near a major metropolitan area, which represents an important contribution to the understanding of fish reproductive ecology in ecosystems with a history of environmental disturbance and recovery such as the Illinois River Waterway.

Penguins and climate change

Read the full story from the University of Delaware.

It’s a big question: how is climate change in Antarctica affecting Adélie penguins?

Climate has influenced the distribution patterns of Adélie penguins across Antarctica for millions of years. The geologic record tells us that as glaciers expanded and covered Adélie breeding habitats with ice, penguin colonies were abandoned. When the glaciers melted during warming periods, this warming positively affected the Adélie penguins, allowing them to return to their rocky breeding grounds.

But now, University of Delaware scientists and colleagues report that this beneficial warming may have reached its tipping point.

In a paper published today in Scientific Reports, the researchers project that approximately 30 percent of current Adélie colonies may be in decline by 2060 and approximately 60 percent may be in decline by 2099.

Wisconsin: Volunteers needed for statewide breeding bird atlas

Read the full story from the Wisconsin Department of Natural Resources.

Organizers of the statewide Wisconsin Breeding Bird Atlas survey are recruiting volunteers to help update information about what birds breed in Wisconsin and where, and they are conducting free field trips June 11-12 in many locations to introduce people to the survey and its methods.

Fish prefer plastic to natural prey

Read the full story in Resource magazine.

When grown, fish that were exposed to microplastics as larvae prefer to eat plastic rather than their natural prey and are less active and responsive to predator cues, threatening the sustainability of entire species, according to research published today (3 June).

A study by researchers at Uppsala University in Sweden, published in the Science journal, exposed Eurasian perch larvae to ‘environmentally relevant concentrations of microplastic polystyrene particles’, and found that they exhibited changed behaviours and stunted growth that led to ‘greatly increased mortality rates’.