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The Delta: California's Big Bass Lake

The Sacramento-San Joaquin Delta was recently awarded a spot among the top ten best black bass fishing locations in the United States -- but given that black bass are not native to California, not everyone will find this distinction a cause for celebration. Bass Master magazine recently ranked the country's 100 best black bass lakes for 2013 based on state wildlife data, fisheries catch rates, and angler recommendations. The Delta garnered the number 9 slot, behind such locations as Clear Lake, California; Lake Eerie; and Lake Okeechobee, Florida. While the term "lake" might at first seem a misnomer for a tidal estuary like the Delta, we have transformed its variable habitats over the decades to a more uniform, lake-like environment, complete with an abundance of warm-water sportfishes (Moyle et al. 2010).


Black bass have a long history in California. This group includes several species: largemouth bass, smallmouth bass, redeye bass, and spotted bass. Bass were first introduced into the Delta in 1874, but have had many additional introductions over the past century. These natives of the eastern and southern United States have now been introduced to waters around the world. Although bass were intentionally stocked in new environments because of their sportfishing appeal, the same aggressive behavior that makes these fish desirable game trophies also makes them a voracious predator, and a threat to other species. Bass can disturb native ecosystems by taking a hefty bite out of native fish populations (Sanderson et al. 2009), and the largemouth bass is now considered one of the ten most invasive species that the United States has exported. Black bass are now also a large component of the most invaded estuary in the world, the Sacramento-San Joaquin Delta (Feyrer and Healey 2003).


The California Department of Fish and Wildlife (CDFW) has played a large role in developing California's world-class bass fishery, which contributes to the state's recreational economy and boasts 21 of the 25 biggest largemouth bass ever caught in the United States. As recently as the 1980s, CDFW stocked a Florida subspecies of largemouth bass (Micropterus salmoides floridanus) in California waters, which are larger, more aggressive, and faster growing than their northern relatives (Dill 1997). The CDFW issues permits for hundreds of fishing tournaments each year, and provides a Trophy Black Bass Certificate Program to recognize trophy-sized black bass anglers. The State of California now hosts more than 1,600 days of tournament fishing per year and Delta tournaments frequently produce bass over 10 pounds. In 2011, anglers caught and released more than 20,000 black bass in Delta tournaments (CDFW 2012). Given the need to restore native species in this highly altered environment where sportfishing is so popular, many people are calling for a re-evaluation of how we view and manage the Delta.

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Planet ocean  

There's no denying two things about our world's oceans: 1) they are really big, and 2) they're a really big deal. The big, blue, vastness of the oceans cover more than 70% of our planet's surface. Some would therefore make the case that our planet ought to be named "Ocean" rather than "Earth." In honor of World Ocean's Day on June 8, we wanted to highlight some of our marine-themed blog posts to show how important the oceans are to anyone who cares about fish, water, or the environment.


The ocean is home to an incredible diversity of fishes. More than 15,700 species of marine fishes have been described, and scientists estimate another 4,000 species await discovery (Mora et al. 2008). This colorful array spans a range of body forms as unique and varied as the ocean sunfish (see Ocean sunbathers), the Pacific viperfish (see Got teeth?), the longnose lancetfish (see Washed up), the salmon snailfish (see Jabba the Hutt?), the spiny lumpsucker (see  Cute or ugly?) -- and who could forget the blob sculpin (see The old man in the sea)? This parade of evolutionary diversity  only scratches the surface of what we know about the ocean and its inhabitants - so much about this watery world remains to be explored, discovered, and understood.


Physical processes in the ocean fuel the food web that sustains marine life (see Wind-powered), and play an important role in the lives of salmon that spend a few ocean-going years fattening up (see Salmon Hunger Games). Migrating salmon are the perfect ambassadors to show us how the watershed connects land and sea, as freshwater flows to saltwater. However, this connectivity also creates problems when runoff water gathers toxic chemicals and pollutants from land and carries them to sea (see Toxic runoff). Our oceans face a host of other threats, from fisheries in decline (see The latest tuna fad)...   Read more>  

IN THE NEWS: Recent stories you might have missed...
EPA survey ranks California No. 1 in water infrastructure needs
Los Angeles Times 

California could use $44.5 billion to fix aging water systems over the next two decades, according to a federal survey that placed the state at the top of a national list of water infrastructure needs. Texas, at nearly $34 billion, and New York, with about $22 billion, were next in line. The assessment, conducted by the U.S. Environmental Protection Agency in 2011 and released Tuesday, is used to document the capital investment needs of public drinking water... Read more> 

In largest dam removal in U.S. history which fish come back?


Over the last two years the largest dam removal in U.S. history has been taking place on the Elwha River in the Olympic Peninsula. Massive amounts of sediment have been released from above the two dams there. So much sediment, that they actually had to put the dam removal on hold temporarily. But the murky water hasn't stopped fish from making the journey upriver to spawn in the newly-available habitat. Mike McHenry stands next to a water treatment plant and a fish hatchery not too far from the mouth of the Elwha River... Read more > 

How to clean up fish farms and raise more seafood at the same time

Last month, we told you about companies that are growing salmon on dry land. That's an effective - but expensive - way to reduce water pollution caused by fish farms. After all, marine aquaculture provides about half of the seafood we eat. So a Canadian researcher named Thierry Chopin is pushing to develop a less expensive technology that could be used to clean up the many fish farms that are already operating in coastal waters. His approach involves creating a whole ecosystem around a fish farm, so the waste generated by the salmon gets taken up... Read more > 

The case of the missing sockeye
Northwest Fisheries Science Center
A team of NOAA scientists is using an advanced network of receivers along the Salmon River in Central Idaho to detect where and why young sockeye salmon are disappearing on their way to the ocean. The initial results have prompted new measures to boost survival of this endangered species.
The research is led by Gordon Axel of the Northwest Fisheries Science Center's Pasco research station. Electronics technicians at the Center worked with a company that specializes in radio-frequency engineering to develop a system... Read more > 
Drunk fish reactions to robotic lady fish help scientists study alcohol

Typically when studying how alcohol affects the brain, scientists use rats and mice, but it could be last call for rodents. The Polytechnic Institute of New York has a new solution about how to study alcohol - drunk fish and robots. The new method is supposed to be more efficient at getting consistent data, and it turns out drunk fish don't behave like drunk humans. The new technique was outlined in the journal Alcohol - a publication that seems relevant to our interests... Read more >