28 • June 5 - 18, 2015 • The Log
thelog.com Opah: The world’s first fully warm-blooded fish By Parimal M. Rohit
SAN DIEGO — No one will ever con- fuse the opah as human, even if the moonfish was recently identified by the National Oceanic and Atmospheric Administration (NOAA) as the first fully warm-blooded fish. According to research published by
NOAA Fisheries last month, the opah, similar to mammals and birds, circu- lates heated blood throughout its body. Being a warm-blooded fish means opahs have a competitive advantage in colder water. Opahs can also swim faster and see more clearly than its cold-blooded counterparts, allowing the large and colorful pelagic organism to be a high-performance predator, NOAA researchers stated. “Before this discovery I was under
the impression this was a slow-moving fish, like most other fish in cold envi- ronments. But because it can warm its body, it turns out to be a very active predator that chases down agile prey like squid and can migrate long dis- tances,” said Nicholas Wegner, a fish- eries biologist with NOAA Fisheries’ Southwest Fisheries Science Center in La Jolla. Wegner was the lead author of a new paper published by NOAA Fisheries identifying opahs as warm- blooded fish.
The team of NOAA researchers dis-
covered opah uses its gills to conduct a “heat exchange,” regulating the cold blood entering its system as it absorbs oxygen from the water. Combined with
the unique location of its gills, opahs are able to maintain an elevated temperature through- out their entire body, even while traveling through colder depths. Helping the fish species stay warm is fatty tissue surrounding the gills, heart and muscles. The fatty tissue helps the opah generate internal heat and keep it insu- lated from colder water temperatures. “There has never been anything like this seen in a fish’s gills before. This is a cool innovation by these animals that gives them a competitive edge. The concept of counter-cur- rent heat exchange was invented in fish long before we thought of it,” Wegner said. Helping opahs maintain warmer blood temperatures: its exter- nal fins. NOAA’s researchers said opahs constantly flap their fins similar to how a bird flaps its wings, helping the fish species maintain high metabolism and speedy reaction times. Generally speaking, fish in colder depth are “slow and sluggish,” the NOAA research team
Advocacy groups issue claim lead tackle ban harmful to economy
By Parimal M. Rohit
ALEXANDRIA, Virginia — A report issued last month by a national fishing advocacy group claims California’s proposed ban on lead fishing tackle would result in the loss of jobs, adversely impact the state’s fishery conservation and habitat restoration efforts and make recreational fishing expensive. In a report published May 21, the
American Sportfishing Association (ASA) and California Coastal Conservation Association predicted a ban on traditional lead-based fishing tackle would adversely impact the fish- ing industry and cut off millions of dollars in conservation funding. If the state formally adopts the pro- posed ban on lead-based fishing tack- le, anglers could be required to use tungsten- or tin-based gear, both asso-
ciations predicted. Bill Shedd, chairman of the Coastal
Conservation Association’s California Chapter, said the report, entitled “Effects on the Ban on Traditional- Based Tackle for Fishing in California on Angler Participation and Associated Economic Measures,” outlines how a ban on lead fishing tackle translates into thousands of jobs and millions of dollars in tax revenue lost. “While California ranks fifth in the nation in number of anglers, we are dead last in terms of per capita partici- pation,” Shedd said. “However, sport- fishing is an important economic gen- erator for our state, and banning lead tackle, as currently being considered by the state of California, is another burden that would increase the cost of fishing, hurt anglers and cost our economy millions of dollars in lost rev- enue and almost 2,600 jobs.” He added lead fishing tackle is eco-
ing water temperature as it swims between 150 and 1,000 feet below the surface. Researchers added the
opah, unlike sharks or tuna, are capable of keeping its entire body warmer than its surrounding environment. Sharks and bluefin tuna also travel at fast speeds while underwater but are only capable of keeping body parts warm; internal organs, such as a shark’s heart, does not stay warm at lower depths. “Nature has a way of sur-
prising us with clever strate- gies where you least expect them. It’s hard to stay warm when you’re surrounded by cold water but the opah has figured it out,” Wegner said. Recent NOAA surveys indicate anglers have reeled in more opah off the California coast in recent years. “Current conditions may
The National Oceanic and Atmospheric Administration declared the opah as the first fully warm-blooded fish. Nick Wegner, a biologist with NOAA’s Southwest Fisheries Science Center, was one of the leading researcher who helped make the discovery.
stated. Wegner and his colleagues found opahs generally have, on average, a muscle temperature about 41 degrees Fahrenheit higher than the surround-
nomical and the “best per- forming option” for anglers. The report’s findings
were based on two surveys: one of 37 tackle manufac- turers and another with 450 anglers who spend $80 annually on lures, flies and terminal tackle. Based upon the respons-
es, the report concluded fishing activity in California would significantly decrease and the price of alternate gear would double, on aver- age, if the state adopted a ban on lead fishing tackle. The report also stated if the price of non-lead flies, lures and terminal tack- le doubled, about 5 percent of California’s anglers would no longer participate in fishing. According to the report’s estimates, a 5 percent decrease in fishing participation equals a loss of about 80,000 anglers, which would translate to $504,000 in decreased rev- enue for wildlife restoration and nearly $3 million in reduced license sales. “The surveys used in the report also suggest that anglers who continue to fish, 18 percent would fish fewer days, each fishing 21 percent fewer days on average,” a statement issued by ASA
The American Sportfishing Association and California Coastal Conservation Association issued a report last month claiming a ban on lead fishing tackle would negatively impact jobs, fishing conser- vation and habitat restoration. Both groups also predicted a lead tackle ban would steer people away from fishing.
about the report said. “Combined with anglers leaving the sport, this would reduce total California angler days and expenditures in recreational fishing by two million fewer angler days, and $173 million in lost revenues.” As many as 2,582 jobs, $113.6 mil- lion in salaries and wages, $24.2 mil- lion in state and local tax revenue and $26.4 million in federal tax revenues are supported by recreational fishing revenues and could be lost, according to the report, if the state banned lead- based tackle. About 3 in 4 tackle manufacturers said it was not technically feasible for them to begin producing non-lead
See LEAD TACKLE page 30
be favoring the fish, or their population may be growing,” a NOAA statement explained. “Opahs are not usually targeted by fisher- men off California but local
recreational anglers and commercial fisheries occasionally catch the species.” For more information about the opah species, visit
goo.gl/Fr8875.
Photo courtesy NOAA
Photo courtesy KeepAmericaFishing
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