Stories tagged habitat destruction
Waterbirds worldwide are in decline.: Long-billed curlew. Photo US Fish & Wildlife Service
Scientists report that over 40% of the world’s waterbirds are declining in population. The problem is most severe in Asia, though all continents are suffering losses.
The problem is habitat. Some of the richest ecosystems are “edge habitats,” where one type of environment meets another – like, where the sea meets the shore. However, a whopping 2/3rds of the world’s human population lives near the sea shore. As our population grows, more of this habitat is developed for human use, leaving less for birds and other wildlife.
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Over fishing causing problems: Large catch of ocean perch taken during a bottom trawl survey. Photo courtesy the NOAA.
It looks like we’re in deep trouble now in regards to the Earth’s seafood supply. A recent report published in the journal Science estimates that the world’s fisheries are in trouble and if nothing is done, they could collapse as soon as 50 years from now.
An international team of researchers and economists examined marine diversity’s role in maintaining ecosystem services on which many human populations depend for survival. The study was led by Boris Worm, an assistant professor of marine biology at Dalhousie University in Halifax, Canada.
“Biodiversity is a finite resource, and we are going to end up with nothing left…if nothing changes,” Worm warned.
Worm and his team studied the impact of species loss in a variety of ecosystems, and the results were the same everywhere they looked.
“Ecosystems that were losing species were always more fragile, always more vulnerable, always more likely to see a whole collapse of fisheries, more likely to show an increase in toxic events like fish kill and things like that,” Worm said.
The study also found that loss of biodiversity is closely linked to declining water quality, ocean dead zones, and other harmful events. World leaders have been aware of destructive fishing practices for some time, especially “bottom fishing” via trawlers, which is thought to cause serious damage to the environment.
Worm compared the close connection between marine communities and their habitats to a house of cards: If one habitat type or species in the system is removed, the entire thing collapses.
Despite the report’s gloomy prediction, all hope is not lost. The trend could be reversed if, as the study suggests, an ecosystem management approach is used to set aside areas that would be completely off-limits to any human activity. At the same time, other regions could be made accessible for recreation, research, fishing, and other such uses.
Jane Lubchenco, an Oregon State University marine biologist, praised the evidence for recovery presented in the study, but cautioned that the rate of implementation of the recovery tools needs to be sped up significantly.
Worm added that individually we can have an effect on fishing practices.
“All of these species end up in our bellies somewhere, so of course we have a lot of control over what is caught and how it is caught, “ he said. “We need to make informed choices on the fish we eat."
MORE INFORMATION
Amazing facts about global fisheries crisis (Greenpeace site)
National Geographic
Historic Global Fisheries Agreement
Monarch butterfly: Courtesy Matt Stratton
The number of butterflies migrating through California has dropped to a forty year low, according to researchers at the University of California, Davis. One-half of the usual species of butterflies have not appeared this season, and other species have been observed in very low numbers. Climate change related to global warming and habitat destruction may be the cause.
Global warming is the increase in the Earth’s average temperature over recent decades primarily attributable to human activities.
Habitat destruction is a change in land use in which one habitat is replaced with another. The plants and animals which previously used the site are destroyed or displaced in the process.
A mild winter in Northern California has caused many species to not end their winter dormancy at the right time. This means that many butterflies emerged too late in the season. The proper climate for breeding was disrupted by a wet spring.
In Southern California, an unusually dry desert left little food for caterpillars of some species to feed on. A late snow in the Sierra Nevada may have killed many insects used for food.
Some species of butterflies that breed several times a year may rebound from these events, but for other species the effects may be devastating for up to a decade.
Read the original press release here.
BirdLife International, a global alliance of conservation groups, has released its annual assessment of world-wide bird populations, and the news isn't good. 2,000 different species — more than one-fifth of the world's total — are either endangered or threatened with extinction. Humans are the biggest threat, either through destroying bird habitats, or by bringing pests and predators to new areas where they hunt defenseless birds. But humans are also the birds' best hope, if we can figure out ways to preserve these species before they disappear.
