Sunday, March 2, 2014
Some years back, researchers in Honolulu learned that the trick to raising mahimahi in captivity was figuring out what they ate when they were still tiny larvae.
Now University of Hawai`i researchers are among those who have developed similar information about wild fish in the deep ocean. Maybe, they suggest, it isn’t overfishing that’s destroying fisheries, but starvation of the keiki.
(Image: The copepod Calanus finmarchicus, superimposed on a map of the Gulf of Maine. credit: Patrick Hassett, Ohio University.)
Petra Lentz and Andrew Christie, researchers with Pacific Biosciences Research Center at the University of Hawai‘i at Mānoa, are among the authors of a new paper that looks at the collapse of the cod fishery and other fisheries in the North Sea.
The paper has the unwieldy title, “De Novo Assembly of a Transcriptome for Calanus finmarchicus (Crustacea, Copepoda) – The Dominant Zooplankter of the North Atlantic Ocean.”
Like mahimahi, when they’re still babies, cod eat tiny oceanic crustaceans called copepods. And recently, the species of copepod that cod larvae prefer have themselves been in collapse. That same copepod is a major food source for other creatures as well, including right whales and Atlantic herring. And since bluefin tuna feed on herring, it's at the base the food chain.
So maybe focusing on regulating the fishermen isn’t the answer to restoring fisheries. Maybe you need to look at what’s starving their babies.
The researchers have developed a new genetic technique for assessing what’s going on with the health of the copepods. It’s very technical stuff, but using an approach called transcriptomics, they can study how the copepods’ cells respond to changes in their environment.
And as they learn how that works, they hope to be able to determine which environmental changes are impacting the copepod health—for instance, whether it's ocean acidification, or changes in water temperature, or altered current patterns, or something else.
The researchers are assuming that something in their environment is preventing the copepod, Calanus finmarchicus, from completing its life cycle. And that means that when cod larvae go looking for breakfast, the table is bare.
Several presentations at the 2014 Ocean Sciences Meeting at the Hawai`i Convention Center in late February described the new techniques, which were developed, in addition to Hawai`i researchers, by team members from Ohio University and Indiana University’s National Center for Genome Analysis Support. Mount Desert Island Biological Laboratory in Maine and the University of Georgia Genomics Facility.
The University of Hawai`i news release on the research is here.
Citation: Lenz PH, Roncalli V, Hassett RP, Wu L-S, Cieslak MC, et al. (2014) De Novo Assembly of a Transcriptome for Calanus finmarchicus (Crustacea, Copepoda) – The Dominant Zooplankter of the North Atlantic Ocean. PLoS ONE 9(2): e88589. doi:10.1371/journal.pone.0088589
© Jan TenBruggencate 2014
Wednesday, February 12, 2014
The U.S. Fish and Wildlife Service is reopening the public discussion of whether the regal Hawaiian hawk, `io, should be removed from the protection of the Endangered Species Act.
The service proposed the removal in 2008, but delayed action after receiving considerable public testimony on the subject. See our previous post, from 2008.And another from 2007.
(Image: Hawaiian hawk, or `io. Buteo solitarius. Credit: Jack Jeffrey/USFWS.)
There is some question whether the hawk should ever have been placed on the endangered species list. Current observations suggest the population is stable at about 3000 birds, and has been stable at that level for at least two decades.
It is also true that the hawk was once found across the archipelago, and now, aside from rare and isolated observations, is only on one island, Hawai`i. A naturalist on Captain James Cook’s voyage to the Islands spotted an `io on Kaua`i. Fossil records have located hawk remains on Kaua`i and Moloka`i. See a FWS fact sheet on the hawk for more information:
The language of the USFWS announcement suggests that some of the assumptions made when the bird was listed may have been incorrect. Says the release: “When originally listed as endangered in 1967, the hawk was presumed to occupy only undisturbed, native habitat and its population was thought to be in the low hundreds. It is now known to occur in a variety of habitat types – at both high and low elevations – that include native forest, nonnative forests, pastures and agricultural lands.”
As early as 1993, the Fish and Wildlife Service was already proposing shifting the hawk’s status from endangered to threatened. At the time, it noted that hawks respond far better to habitat modification—like logging and transitions from native forest to agriculture and pasture, than other native birds.
“The hawk may be one of the few native Hawaiian birds with the versatility to adapt to a changing landscape,” the service wrote at that time.
The 1993 proposed downlisting was never acted upon, and in 2008, the service proposed delisting instead. But it delayed action after hearing from lots of folks on the topic.
“Information gathered during previous comment periods has caused us to reexamine our original proposal. We encourage all interested parties to provide information pertinent to the proposed delisting of the Hawaiian hawk,” said USFWS Pacific Islands field supervisor Loyal Mehrhoff.
The public comment period on the proposed rule to delist the hawk will be open for 60 days. The deadline for submitting comments is April 14, 2014.
For more information see the Fish and Wildlife Service website at http://www.fws.gov/pacificislands/, or visit http://www.regulations.gov and follow instructions for submitting comments on Docket No. FWS–R1–ES–2007-0024.
© Jan TenBruggencate 2014
Sunday, February 9, 2014
Enjoy the rain in Hawai`i the last couple of months, because there’s some evidence that later this year we could face the opposite: unusually dry conditions.
Researchers are detecting an increasing likelihood that we’ll be moving into an El Nino climate condition in the second half of this year. One of the hallmarks of an El Nino in Hawai`i is winter and spring drought. Another is increased tropical cyclone frequency.
(Image: Noaa water temperature chart from the extreme El Nino event of 1997. Credit: NOAA.)
In its Feb. 6, 2014, El Nino diagnostic discussion, U.S. Climate Prediction Center said that after the spring, there appears an increasing likelihood of a new El Nino event.
While warning that El Nino forecasts are notoriously hazy in the spring, the CPC says “an increasing number of models suggest the possible onset of El Niño. Strong surface westerly winds in the western Pacific and the slight eastward shift of above-average temperatures in the subsurface western Pacific potentially portend warming in the coming months.”
The CPC report follows on the heels of a similar prediction January30, 2013, by the World Meteorological Organization.
The WMO cited models that predicted Nino-neutral conditions through the spring, and chances of continued neutral conditions or a weak El Nino in the third quarter of the year.
The Australian Bureau of Meteorology chimed in even earlier, on January 28, 2014, with great caution, but a suggestion that neutral conditions could remain in place into the fall, but that El Nino warming could ease into place toward the end of the year.
“Most climate models surveyed by the Bureau suggest the tropical Pacific Ocean will warm through the southern autumn and winter. Some, but not all, models predict this warming may approach El Niño thresholds by early winter. Model outlooks that span autumn have lower skill than forecasts made at other times of the year, hence long-range model outlooks should be used cautiously at this time,” the Australian service reported.
Thus far, none of the prediction services are proposing that the El Nino, if it comes, will be a strong one. But they sometimes are, and one group of researchers suggests we’ll be seeing more of those.
It was 15 years between an extremely strong El Nino in the 80s and the one in the late 90s, and it’s been a similar period of time from then till now. A paper in the journal Nature Climate Change notes that extreme El Ninos occurred in 1982-83 and again in 1997-98.
That paper suggests we could be seeing more of those in the future, thanks to climate change. In fact, we could see twice as many extreme El Nino events as we see now, the authors argue.
“The increased frequency arises from a projected surface warming over the eastern equatorial Pacific that occurs faster than in the surrounding ocean waters, facilitating more occurrences of atmospheric convection in the eastern equatorial region,” they write.
© Jan TenBruggencate 2014
Saturday, February 8, 2014
With the Olympics going on in Russia, it’s not clear why the local media haven’t picked up on perhaps the most amazing athletic performance in the animal world—at the western end of the Hawaiian archipelago.
That’s where the oldest wild bird known has just produced another offspring.
(Image: If there were Olympic medals for this, she’d get one. Wisdom the 63-year-old Laysan albatross on Midway Atoll with her new chick. Credit: USFWS photo by Ann Bell.)
The Laysan albatross nicknamed “Wisdom” has been faithfully producing new albatrosses for more than half a century. Wisdom is at least 63 years old—she was already a mature adult when she was banded in 1956.
This year, she is raising yet another chick. Like other albatross, she will fly thousands of miles to collect food for the youngster—as she has for her earlier offspring for decades. It is estimated that Wisdom and her mate have raised 30 to 35 young in their lives, and maybe more. She produced one last year as well, and one at age 60 in 2011.
Dan Clark, manager of the Midway Atoll National Wildlife Refuge, within the Papahānaumokuākea Marine National Monument, called the bird an “inspiration and hope for all seabird species.”
“She provides to the world valuable information about the longevity of these beautiful creatures. In the case of Wisdom, she has logged literally millions of miles over the Pacific Ocean in her lifetime to find enough fish eggs and squid to feed herself and multiple chicks, allowing us the opportunity to measure the health of our oceans which sustain albatross as well as ourselves,” Clark said.
To be clear about how remarkable this is, Wisdom is a fully functioning and reproducing albatross at twice the normal albatross life span. If you go here, they’ll tell you the lifestpan of a normal Laysan albatross is 12 to 40 years.
Wisdom has survived and thrived in the face of significant threats to her species.
“It is a poignant and overwhelming reality that plastics discarded at sea float, from toothbrushes to millions of bottle caps, float and, are used as a substrate for flying fish to attach their eggs, a food highly prized by foraging albatross and ultimately regurgitated into the chick’s mouth,” said refuge biologist Pete Leary.
For more information on Midway Atoll National Wildlife Refuge and the Battle of Midway National Memorial go here.
See the FWS press release, with more pictures and background on Laysan albatrosses.
© Jan TenBruggencate 2014
Tuesday, February 4, 2014
Life doesn’t operate in black and white.
If we’re honest, we admit that the things we like have negative impacts, and the things we hate may include positives. Shades of gray.
Take forest management. We can all agree that clearcutting a forest has devastating, even catastrophic impacts. The forest, after all, is entirely removed, even if it or some semblance of it may be regrown later.
You might assume that human collection of non-timber resources in the forest is, by contrast, pretty benign. Like collection of fruits or flowers or roots for medicine, tapping of trees for their latex to make rubber, wandering the Hawaiian forest for maile.
(Image: Prized Hawaiian forest vine, maile. Credit: Forest & Kim Starr.)
But as benign as they might seem when compared to logging, these activities also have impacts, ranging from minor to very significant.
University of Hawai`i botany professor Tamara Ticktin, a conservation biologist and ethnoecologist, has studied these issues, and her insights have some weight. The British Ecological Society recently named one of her papers one of the 100 most influential among the 17,000 papers it has published.
That 2004 paper was titled, “The ecological implications of harvesting non-timber forest products.” It is available here.
Ticktin herself said the strength of the paper may be that it had pulled together a great deal of information that previously had not been collected in one place.
“Prior to the Ticktin article, our knowledge of the ecological consequences of non-timber forest product extraction was disparate, and spread out across many different case studies. Ticktin made an important advance by systematically reviewing the conclusions of 70 different studies from across the world,” wrote Jos Barlow in a review for the British Ecological Society.
In an interview, Ticktin said there have been widely different views of non-timber harvest—anywhere from the view that any activity by humans is harmful, to the view that traditional collecting in forests is largely benign.
In the paper, she makes the point that “extraction of non-timber plant parts may alter biological processes at many levels.” And dramatically increasing the harvest can turn a relatively non-impactful activity into one with significant negative consequences for the forest.
“One of the take-homes is that it depends on local knowledge. It’s how you do it,” she said.
Reviewer Barlow, an ecologist himself, wrote: “the good news is that some management techniques can be effective at reducing the negative impacts of harvesting. These include enrichment planting, shade management, and focussing on non-lethal harvesting activities that do not affect the population of adult stems (such as the harvesting of bark, fruits, latex and resins).”
As a local example, Ticktin said she has a student looking into methods of harvesting the scented lei vine, maile, in Hawaiian forests. "Improper harvest techniques could damage the plants, while careful, informed harvesting could have no effect or could even stimulate growth" she said.
It can also depend on what plant is being harvested, and what part of the plant is being harvested. Examples of collection goals: There are different impacts from stripping new growth from maile, collecting fruits from mokihana or pulling entire hapu`u plants out of the forest.
None is as destructive as clearcutting, but neither is any entirely without impact.
Shades of gray.
© Jan TenBruggencate 2014