Julia Whitty

Julia Whitty

Environmental Correspondent

Julia is an award-winning author of fiction and nonfiction (Deep Blue Home, The Fragile Edge, A Tortoise for the Queen of Tonga), and a former documentary filmmaker. She also blogs at Deep Blue Home.

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Julia is a writer and former documentary filmmaker and the author of The Fragile Edge: Diving & Other Adventures in the South Pacific, winner of a PEN USA Literary Award, the John Burroughs Medal, the Kiriyama Prize, the Northern California Books Awards, and finalist for the Dayton Literary Peace Prize, and Deep Blue Home: An Intimate Ecology of Our Wild Ocean. Her short story collection A Tortoise for the Queen of Tonga won an O. Henry and was a finalist for the PEN Hemingway Award. She also blogs at Deep Blue Home.

Chile's Mega-Quake Restored Beaches and Biodiversity

| Fri May. 4, 2012 11:41 AM PDT

 Chilean coast after the 2010 tsunami.: Marcelo Caro via Wikimedia Commons

Chilean coastal town after the 2010 tsunami: Marcelo Caro via Wikimedia Commons

The study is believed to be the first-ever quantification of earthquake and tsunami effects on sandy beach ecosystems along a tectonically active coastal zone.

Chile's 8.8 earthquake and tsunami of 2010 caused massive devastation, not least along its coastline, with some beaches subsiding and losing biodiversity, and some rocky reefs uplifting  and losing biodiversity—as you might expect.

But thanks to the investigations of a science team already looking at the ecology of Chile's sandy beaches before the quake, we now know this natural disaster also engineered some powerful and unexpected forms of coastal restoration. 

This occurred where the temblor uplifted coastlines with coastal armouring—like seawalls and rocky revetments—which allowed those once-disappearing beaches to quickly grow where they had not grown in a long time, and allowed plants and other species to reinhabit places they hadn't inhabited in a long time.

The study, just published in the open-access PLoS ONEalso previews the types of changes we might expect from climate warming and its accompanying sea level rise. 

 

Photos of study sites taken before and after the 2010 Chile earthquake: Eduardo Jaramillo, et al. PLoS ONE. DOI:info:doi/10.1371/journal.pone.0035348.g002Photos of study sites taken before and after the 2010 Chile earthquake: Eduardo Jaramillo, et al. PLoS ONE. DOI:info:doi/10.1371/journal.pone.0035348.g001

In the before-and-after disaster above the orange dotted lines indicate 24 hour spring high tide line. You can see that dry sandy areas above the high tide line dwindled where beaches that subsided (a) and increased where beaches uplifted (b, c and d). These changes were affected by whether or not coastal armoring was in place. Specifically

  • a–b show unarmored sites (a: where land subsided and the beach grew narrower after the quake; b: where coastal uplift made the beach wider afterwards)
  • c–d show armored sites (c: where uplifted wider intertidal occurs in conjunction with a seawall; d: where uplifted wider intertidal occurs in conjunction with a revetment)
  • e–f show relationships between the magnitude of land-level changes (e: shows beach widths; f: shows beach face slopes—red dots=sites with seawalls; blue dots=sites with rocky revetments; black dots=unarmored sites)

 

Land level changes from the 2010 Chile earthquake, epicenter yellow star: Eduardo Jaramillo, et al. PLoS ONE.

Land level changes from the 2010 Chile earthquake, epicenter yellow star: Eduardo Jaramillo, et al. PLoS ONE. DOI:info:doi/10.1371/journal.pone.0035348.g001

"So often you think of earthquakes as causing total devastation, and adding a tsunami on top of that is a major catastrophe for coastal ecosystems," says co-author Jenny Dugan, at UCSB"As expected, we saw high mortality of intertidal life on beaches and rocky shores, but the ecological recovery at some of our sandy beach sites was remarkable. Plants are coming back in places where there haven't been plants, as far as we know, for a very long time. The earthquake created sandy beach habitat where it had been lost. This is not the initial ecological response you might expect from a major earthquake and tsunami."

From the paper:

Ecological effects of extreme events, such those we observed for the [Chile] event, are expected to vary in duration. Shorter-term effects on beaches included direct mortality associated with the tsunami and the indirect bottom up effects of increased inputs of algal wrack from uplifted rocky shores on upper shore invertebrate consumers such as talitrid amphipods (Orchestoidea tuberculata). However, in areas with significant uplift (ca. 2 m), locations of armoring structures were shifted higher on the beach profile, reducing interaction with waves and tides and restoring intertidal zones for biota and ecological function. For this reason we expect positive changes observed in these beach ecosystems to persist, altering intertidal community composition and dynamics over the long term, even in front of existing coastal armoring. In contrast, for the subsided armored areas, community composition and population abundances are expected to remain depressed over time.

 

The paper:

  • Jaramillo E, Dugan JE, Hubbard DM, Melnick D, Manzano M, et al. (2012) Ecological Implications of Extreme Events: Footprints of the 2010 Earthquake along the Chilean Coast. PLoS ONE 7(5): e35348. doi:10.1371/journal.pone.0035348

 

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Scientists: Extinctions Just as Damaging as Climate Change

| Wed May. 2, 2012 11:18 AM PDT

 Amazon rainforest: Phil P Harris via Wikimedia Commons.

Amazon rainforest: Phil P Harris via Wikimedia Commons.

A new paper in the prestigious science journal Nature assesses one of the big questions in ecology today: How do species extinctions rack up compared to other global change issues like global warming, ozone holes, acid rain, and nutrient pollution (overfertilization)?

"Evidence is mounting that extinctions are altering key processes important to the productivity and sustainability of Earth's ecosystems."

The answer: Just as nasty. In fact species loss is likely to rank among the top five drivers of global change.

"Some people have assumed that biodiversity effects are relatively minor compared to other environmental stressors,” says lead author David Hooper of Western Washington University. "Our new results show that future loss of species has the potential to reduce plant production just as much as global warming and pollution."

Studies in the past 20 years have demonstrated that more biologically diverse ecosystems are more productive. So there's growing concern that the very high rates of modern extinctions from habitat loss, overharvesting, pollution, biological invasions, human overpopulation, and other human-caused environmental changes will diminish nature's ability to provide goods and services important to all life (ours too)... like food, clean water, and a stable climate. 

A schematic image illustrating the relationship between biodiversity, ecosystem services, human well-being, and poverty: Millennium Ecosystem Assessment via Wikimedia Commons

Schematic illustrating the relationship between biodiversity, ecosystem services, human well-being, and poverty, and where we can improve our strategies: Millennium Ecosystem Assessment via Wikimedia Commons  

"The biggest challenge looking forward is to predict the combined impacts of these environmental challenges to natural ecosystems and to society," said co-author J. Emmett Duffy at the Virginia Institute of Marine Science. 

The team performed a meta-analysis of published data from 192 earlier studies to assess the effects of extinctions on productivity and decomposition:

  1. Productivity (the rate of production of biomass in an ecosystem, starting with plants producing life from sunlight)
  2. Decomposition (the work done by bacteria and fungi that releases nutrients back for recycling by the producers)

The stats:

  • At intermediate levels of species loss (21–40%), plant production is reduced by 5–10%, comparable to previously documented effects of ultraviolet radiation (ozone hole) and global warming.
  • At higher levels of species extinction (41–60%), dwindling productivity rivals the effects from ozone holes, acid rain, global warming, and nutrient pollution (overfertilization).
  • At intermediate levels, species loss had equal or greater effects on decomposition compared to global warming and nutrient pollution.

From the paper:

[O]ur analyses clearly show that the ecosystem consequences of local species loss are as quantitatively significant as the direct effects of several global change stressors that have mobilized major international concern and remediation efforts.

 

The video is the best short describing the importance of biodiversity that I've seen.

The paper:

  • David U. Hooper, E. Carol Adair, Bradley J. Cardinale, Jarrett E. K. Byrnes, Bruce A. Hungate, Kristin L. Matulich, Andrew Gonzalez, J. Emmett Duffy, Lars Gamfeldt & Mary I. O’Connor. A global synthesis reveals biodiversity loss as a major driver of ecosystem change. Nature (2012) doi:10.1038/nature11118

 

It's Okay to Eat Sardines...Right?

| Mon Apr. 30, 2012 3:00 AM PDT

Sardines (Sardina pilchardus): Etrusko25 via Wikimedia CommonsSardines (Sardina pilchardus) Etrusko25 via Wikimedia Commons

Sardines are considered a sustainable seafood, one of the few fish you can eat guilt-free, right? Well, not exactly. Forage fish like sardines and anchovies are the key players in huge but delicate food webs known as wasp-waist ecosystems. These are so complex and dynamic that it's questionable whether we have the know-how to manage them well yet. And as we've learned the hard way from examples off California, Peru, Japan, and Namibia, wasp-waist ecosystems collapse catastrophically whenever the stresses of climate change intersect with the stresses of overfishing (see Andrew Bakun, et al., below*).

These systems are often driven by multiyear, even multidecadal, climate patterns like El Niño and La Niña—natural boom-and-bust cycles that remain largely beyond our abilities to scientifically manage. And while some overfished wasp-waist ecosystems have recovered after decades of fishing moratoria (California, Peru), others have not (Japan, Namibia). Some, like Peru, collapse repeatedly.

Global capture of sardines in the Sardinops genus in tonnes, 1950–2010, as reported by the FAO. Based on data sourced from the relevant FAO Species Fact Sheets: Epipelagic via Wikimedia Commons

Global capture of sardines in the Sardinops genus in tons, 1950–2010, as reported by the FAO. Based on data sourced from the relevant FAO Species Fact Sheets. Epipelagic via Wikimedia Commons 

I wrote about the downside of the sardine fishery in Mexico's Gulf of California in my latest Mother Jones print piece, "Can One Incredibly Stubborn Person Save a Species?" This is the story of my old friend Enriqueta Velarde's efforts to save the seabirds and other wildlife of the Gulf. Year after year she's taken on staggering problems. Today her biggest fear is the rapidly growing sardine fishery:

She's concerned because the Gulf of California sardine fishery, Mexico's largest by volume, landed more than a quarter million metric tons the year before. She knows the Gulf is a wasp-waist ecosystem: ecology-speak for a delicate food web dependent on forage fish (sardines and anchovies) that are virtually the only predators of all below them (plankton) and virtually the only prey of the tiers above them (bigger fish, seabirds, marine mammals)…Mexico just received a sustainability certification for its sardine fishery from the Marine Stewardship Council, which would vastly increase market demand in the US. Velarde fears that the fish, keystone to all Gulf species—including humans—will crash.

 

Tern with fish: Badjoby via Wikimedia Commons

Tern with fish Badjoby via Wikimedia Commons 

But it's the Marine Stewardship Council, and you can trust what they say is okay to eat is okay, right? Well, not necessarily. As I've written here about swordfish, here about Chilean sea bass, and here about pollock, hake, Antarctic toothfish, and krill, there are increasing concerns among scientists about the criteria the MSC is using to certify fisheries as sustainable.

So before you take a bite of that sardine sandwich, you might think about all the truly vast ecosystems—composed of seabirds, bigger fish, seals, dolphins, whales, and sharks—utterly dependent on sardines and their kin. And the fact our fisheries management might not yet be capable of managing what we don't yet fully understand.

*Papers:

  • Andrew Bakun, Elizabeth A. Babcock, Salvador E. Lluch-Cota, Christine Santora, Christian J. Salvadeo. Issues of ecosystem-based management of forage fisheries in "open" non-stationary ecosystems: the example of the sardine fishery in the Gulf of California. Rev Fish Biol Fisheries. 2009. DOI 10.1007/s11160-009-9118-1
  • Andrew Bakun. Wasp-waist populations and marine ecosystem dynamics: Navigating the "predator pit" topographies. Prog Oceanography. 2006. DOI:10.1016/j.pocean.2006.02.004

 

Reef Sharks Vanishing Around Populated Islands

| Fri Apr. 27, 2012 1:45 PM PDT

Gray reefs sharks: Albert kok via Wikimedia CommonsGray reefs sharks: Albert kok via Wikimedia Commons

A new study finds that sharks living on reefs near areas populated by people have declined by between 90 and 97 percent compared to relatively pristine reefs where few or no people live.

"We estimate that reef shark numbers have dropped substantially around populated islands, generally by more than 90 percent compared to those at the most untouched reefs," says Marc Nadon, lead author of the study.

The authors of the paper in early view at Conservation Biology deployed 1,607 towed-diver surveys—that's where scientists are used as shark bait (kidding, sort of)—to count sharks at 46 reefs in the central-western Pacific Ocean. They combined those data with information on human population, habitat complexity, and reef area, as well as with satellite-derived measurements of sea surface temperature and oceanographic productivity.

These methods allowed them to fill in the blanks on the numbers of missing sharks. Their models showed that:

  • Densities of gray reef sharks (Carcharhinus amblyrhynchos), whitetip reef sharks (Triaenodon obesus), and other reef sharks increased substantially as human population decreased. 
  • Densities of reef sharks increased substantially as primary productivity and minimum sea surface temperature (which correlates to reef area) increased.

From the paper:

Simulated baseline densities of reef sharks under the absence of humans were 1.1–2.4 [per hectare] for the main Hawaiian Islands, 1.2–2.4 [per hectare] for inhabited islands of American Samoa, and 0.9–2.1 [per hectare] for inhabited islands in the Mariana Archipelago, which suggests that density of reef sharks has declined to 3–10% of baseline levels in these areas.

 

Blacktip reef sharks: Jon Rawlinson via Wikimedia CommonsBlacktip reef sharks: Jon Rawlinson via Wikimedia Commons

"[Sharks] like it warm, and they like it productive," said Julia Baum, Assistant Professor at the University of Victoria, Canada, referring to the increase in reef sharks the team found in areas with higher water temperatures and productivity. "Yet our study clearly shows that human influences now greatly outweigh natural ones."

The paper:

  • NADON, M. O., BAUM, J. K., WILLIAMS, I. D., MCPHERSON, J. M., ZGLICZYNSKI, B. J., RICHARDS, B. L., SCHROEDER, R. E. and BRAINARD, R. E. (2012), Re-Creating Missing Population Baselines for Pacific Reef Sharks. Conservation Biology. doi: 10.1111/j.1523-1739.2012.01835.x

 

Big Changes in Ocean Salinity Intensifying Water Cycle

| Thu Apr. 26, 2012 1:56 PM PDT

Surface salinity changes for 1950 to 2000. Red indicates regions becoming saltier, and blue regions becoming fresher: P.J. Durack, et al. 2012. Science. DOI:10.1126/science.1212222

Surface salinity changes from 1950 to 2000. Red shows regions becoming saltier, blue regions becoming fresher:  P.J. Durack, et al. Science. 2012. DOI:10.1126/science.1212222

A paper in Science today finds rapidly changing ocean salinities as a result of a warming atmosphere have intensified the global water cycle (evaporation and precipitation) by an incredible 4 percent between 1950 and 2000. That's twice the rate predicted by models. 

These same models have long forecast that dry areas of Earth will become drier and wet areas wetter in a warming climate—an intensification of the water cycle driven mostly by the capacity of warmer air to hold and redistribute more moisture in the form of water vapor.

satellite image shows the distribution of water vapor over Africa and the Atlantic Ocean on  2 Sept 2010: NASASatellite image shows the distribution of water vapor over Africa and the Atlantic Ocean on 2 Sept 2010: NASA

But the rate of intensification of the global water cycle is happening far faster than imagined: at about 8 percent per degree Celsius of ocean warming since 1950.

At this rate, the authors calculate:

  • The global water cycle will intensify by a whopping 16 percent in a 2°C warmer world
  • The global water cycle will intensify by a frightening 24 percent in a 3°C warmer world

 

A schematic representation of the global water cycle, with the key role of the ocean and surface rainfall and evaporation fluxes expressed: Durack et al. Science. 2012. DOI:10.1126/science.1212222

A schematic representation of the global water cycle, with the key role of the ocean and surface rainfall and evaporation fluxes expressed: Durack et al. Science. 2012. DOI:10.1126/science.1212222 

The changes will not be uniform across the globe, but trend toward increased drying of arid areas and  increased flooding of wet areas.

And the resulting changes in freshwater availability are likely to be far more destabilizing to human societies and ecosystems than warming alone. 

"Changes to the global water cycle and the corresponding redistribution of rainfall will affect food availability, stability, access, and utilization," says lead author Paul Durack at the University of Tasmania and the Lawrence Livermore National Laboratory.

The paper:

  • Paul J. Durack, Susan E. Wijffels and Richard J. Matear. Ocean Salinities Reveal Strong Global Water Cycle Intensification During 1950 to 2000. Science 2012. DOI:10.1126/science.1212222
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