Understanding the ocean
THE article by Graham Lloyd will likely leave a mis-impression with many of your readers concerning the substance of our paper that will appear in the Journal of Physical Oceanography (“Puzzle of deep ocean cooling”, 25/7).
We never assert that global warming and warming of the oceans are not occurring — we do find an ocean warming, particularly in the upper regions.
Contrary to the implications of Lloyd’s article, parts of the deep ocean are warming, parts are cooling, and although the global abyssal average is negative, the value is tiny in a global warming context.
Those parts of the abyss that are warming are most directly linked to the surface (as pointed out by Andy Hogg from the ANU).
Scientifically, we need to better understand what is going on everywhere, and that is an issue oceanographers must address over the next few years — a challenging observational problem that our paper is intended to raise.
Carl Wunsch, Harvard University and Massachusetts, Institute of Technology
Fine @paultough @nytmag story of man-overboard survival recalls a chilling memory of an empty sloop sailing onto a Sri Lanka beach. In 1979, when I was first mate on the circumnavigating sailboat Wanderlust, we finished our transit of the Bay of Bengal and arrived in Trincomalee, Sri Lanka.
A familiar sailboat was at the pier, but its rig was in tatters. I’d met the owner, a shy Belgian singlehander, in Bali, Indonesia, a few months earlier. The Trincomalee harbormaster said the boat had sailed up onto the beach with nobody aboard, held on course by a wind-vane autopilot.
He showed me the odds and ends taken from the boat, which he’d stored in a caged area in his office. It was clear from the log, and the situation, that the singlehanded sailor, obviously unharnessed, had fallen overboard in mid ocean…
Sri Lanka is a very hot place, but I felt a very deep chill that day.
.@Reuters jumps PNAS embargo & utterly botches story on new @PIK_climate study of sea level rise per degree warming.
Story headline: “Models point to rapid sea-level rise from climate change”
Paper title (italics added): “The multi-millennial sea-level commitment of global warming”
Paper: “[W]e are committed to a sea-level rise of about 2.3 meters [per 1ºC] within the next 2000 years.”
At least Reuters got in a solid quote from lead author Anders Levermann that makes the right point on the right time scale:
"Continuous sea-level rise is something we cannot avoid unless global temperatures go down again," Levermann said. "Our results indicate that major adaptation at our coastlines will be necessary. It’s likely that some currently populated regions can’t be protected in the long run."
Via @pewenvironment: Big problem for big tuna (wasted catch):
According to new data just released by the National Oceanic and Atmospheric Administration’s Fisheries Service (NOAA Fisheries), the surface longline fishery in the Gulf of Mexico and Atlantic wasted almost 25 percent of the entire U.S. bluefin tuna quota. These new estimates show the highest levels of dead discards of bluefin caught on surface longlines since 1987.Surface longlines intended for swordfish, yellowfin tuna, and other tunas (excluding bluefin) stretch for up to 40 miles with hundreds of baited hooks.
In 2012, surface longline vessels discarded an estimated 239.5 mt of dead Atlantic bluefin. Many of those were caught in the Gulf of Mexico—the western population’s only known spawning area. The 239.5 mt statistic does not include 89.6 mt of fish landed (kept and sold) or those thrown back “alive,” many of which will die following release.
In response to these staggering numbers, as of June 25, NOAA Fisheries will prohibit surface longline vessels from keeping any more bluefin tuna caught this calendar year. However, that solution does nothing to prevent those same vessels from catching bluefin tuna while targeting yellowfin tuna and swordfish. Fishermen will need to throw overboard all of those bluefin; many will already be dead or dying.
A solution at hand
NOAA Fisheries is drafting new proposed bluefin tuna regulations, due out this summer. The agency could finally put forth a comprehensive solution to this decades-old problem that is only getting worse. The rule must:
· Close the Gulf of Mexico to surface longlining to protect spawning bluefin tuna and support the transition of surface longlines to more selective fishing methods;
· Reduce bluefin mortality in the western Atlantic by enforcing a firm annual limit on the incidental catch of bluefin for the entire surface longline fleet; and
· Improve monitoring of the surface longline fleet.
Once the agency publishes its rule, a comment period will immediately follow. During this time, the public can contact NOAA Fisheries and urge it to put forth a strong rule that stops the waste of bluefin tuna.
On a related note, fisheries managers and scientists from around the world are preparing to meet in Montreal, Canada next week (June 26-28). They will debate the potential recovery of western Atlantic bluefin tuna; the same fish that these new data suggest are being senselessly wasted. The outcome of the meeting will signal whether fisheries managers will choose tofollow the sound science that is necessary to allow this tuna population to recover or ignore precaution and return to crippling levels of overfishing. The latter could result in the collapse of the western Atlantic bluefin population.
Tom Wheatley, who manages bluefin tuna conservation efforts in the U.S. for The Pew Charitable Trusts, is available to discuss the new bycatch data, its implications and the forthcoming proposed bluefin rule. Amanda Nickson, director ofglobal tuna conservation for Pew, will moderate a tele-press briefing this Thursday at 10 am EDT on next week’s bluefin meeting. Please let me know if I can get you any more information or set up any interviews.