In science news this week: Providing Flows for Fish; Managing a Non-Native Delta Ecosystem; Rare California trout species returns to native habitat; New proposal for expanded killer whale critical habitat reflects latest science; How rock expands near soil surface in Southern Sierra Nevada; Salt marshes’ capacity to store carbon may be threatened by nitrogen pollution; Are existing laws enough to cope with accelerating environmental change?
Providing Flows for Fish: “A reality in California and the American West is that people are competing with fish for water. We humans are winning the competition. However, because there are moral, aesthetic, and legal obligations to provide fish with water in streams, biologists like me often get asked the question “Just how much water do the fish need, anyway?” This, of course, is the wrong question because the best reply is “all of it!” if you consider the stream flows under which each fish species evolved, that often varied from raging torrents to gentle summer trickles across a single year. The question may then switch to, “well, what is the minimum flow we need to provide to keep the fish alive?” This is also the wrong question because if you keep a stream fish assemblage on minimum flows for a long enough period, most native species will likely disappear. In their place will be trout raised in hatcheries and non-native species like fathead minnows and green sunfish; these fish will live in a highly degraded habitats, signified by dead riparian trees and stagnant pools. A more useful question is “what is the optimal flow regime that will allow a diverse native fish fauna and other biota to thrive, while providing water for use by people?” … “ Read more from the California Water Blog here: Providing Flows for Fish
Managing a Non-Native Delta Ecosystem: “The Sacramento–San Joaquin Delta has more non-native species than native ones, and its estuary is considered the most invaded in the world. We talked to Jim Cloern—an emeritus scientist with the US Geological Survey and an adjunct fellow at the PPIC Water Policy Center—about this challenge. PPIC: How have non-native species changed the Delta? Jim Cloern: The plant and animal communities are very different than they were 50 years ago. There are more than 200 non-native species of animals and plants in the Bay and Delta; all were introduced by people, many in the last half century. Some of these introduced species are relatively low in abundance, but some have emerged as “keystone species.” That means they now play a prominent role in the ecosystem, either by changing processes like food production for fish or by reshaping biological communities. … “ Read more from the PPIC blog here: Managing a Non-Native Delta Ecosystem
Rare California trout species returns to native habitat: “For the first time in nearly a century, a rare California trout species will swim in a mountain creek that is its native habitat, marking a major milestone that conservationists hope will lead to a thriving population and removal of its threatened status. About 30 Paiute cutthroat trout will be plucked Wednesday from Coyote Valley Creek in the eastern Sierra Nevada wilderness and hauled in cans strapped to pack mules about 2 miles (3.2 kilometers) west into Long Valley. State and federal researchers will be on hand as the fish are dumped into a stretch of Silver King Creek at around 8,000 feet (2,438 meters) elevation, where the shimmering species glided through the cold water for thousands of years below a waterfall before they started disappearing in the 1920s. … ” Read more from Phys Org here: Rare California trout species returns to native habitat
New proposal for expanded killer whale critical habitat reflects latest science: “Research over the past decade has confirmed that endangered Southern Resident killer whales are truly a West Coast species, feeding on salmon as far south as California. Now NOAA Fisheries is proposing to expand their critical habitat based on information about their coastal range and habitat use. The proposal would extend critical habitat for the whales along a roughly 1,000-mile swath of West Coast waters between the depths of 6.1 meters (20 feet) and 200 meters (about 650 feet) from Cape Flattery, Wash., south to Point Sur, California, just south of Santa Cruz and Monterey Bay. The additional area covers roughly 15,626 square miles, or more than 10 million acres. … ” Read more from NOAA here: New proposal for expanded killer whale critical habitat reflects latest science
How rock expands near soil surface in Southern Sierra Nevada: “A University of Wyoming researcher and his team discovered that weathering of subsurface rock in the Southern Sierra Nevada Mountains of California occurs due more to rocks expanding than from chemical decomposition, as previously thought. Porosity, the void space in rock, was conventionally thought to be produced when water flows through the rock, thus resulting in minerals chemically dissolving. Because mountain watershed provides large reservoirs of water, the new findings are relevant to water resource management throughout the U.S. … ” Read more from Science Daily here: How rock expands near soil surface in Southern Sierra Nevada
Salt marshes’ capacity to store carbon may be threatened by nitrogen pollution: “Deep in the waterlogged peat of salt marshes, carbon is stored at much greater rates than in land ecosystems, serving as an offset to climate change caused by carbon dioxide (CO2) build-up in the atmosphere. But a new study led by scientists at the Marine Biological Laboratory (MBL), Woods Hole, and Northeastern University indicates that a common pollutant of coastal waters, nitrate, stimulates the release of CO2, possibly altering the capacity of salt marshes to hold carbon over time. … ” Read more from the National Science Foundation here: Salt marshes’ capacity to store carbon may be threatened by nitrogen pollution
Are existing laws enough to cope with accelerating environmental change? “Do you think that major statutory reform is necessary address global environmental challenges? Think again. Newly published research published today in the Proceedings of the National Academy of Sciences by a group of environmental law scholars explores the untapped capacity of existing environmental and natural resources management statutes to address accelerating environmental change in the absence of major legislative reform. … ” Read more from Science Daily here: Are existing laws enough to cope with accelerating environmental change?
Maven’s XKCD Comic Pick of the Week …
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About Science News and Reports: This weekly feature, posted every Thursday, is a collection of the latest scientific research and reports with a focus on relevant issues to the Delta and to California water, although other issues such as climate change are sometimes included. Do you have an item to be included here? Submissions of relevant research and other materials is welcome. Email Maven