Tuesday, October 30, 2012

The impact of flooding on the Indus River dolphin

This is a report on a project led by Gill Braulik, Ph.D. and the Pakistan Wetlands Program and supported with a grant from the Aquarium’s Marine Conservation Action Fund (MCAF) in 2010. MCAF supports the Aquarium’s commitment to ocean conservation by funding small-scale, high-impact projects across the globe. Since its founding in 1999, MCAF has funded more than 100 conservation projects in 36 countries and has disbursed more than $600,000 to protect highly vulnerable species and habitats and to conserve marine biodiversity. 


The Indus River dolphin (Platanista gangetica minor) is one of the world’s most threatened marine mammals, with a population size estimated at approximately 1,550 to 1,750 individuals (Braulik et al 2012). The dolphin, which occurs only in the Indus River system in Pakistan and India, has been heavily impacted by poaching, bycatch and pollution. However, the biggest threat to its survival is the fragmentation of its habitat by the dams and barrages that have been constructed on the Indus River for irrigation and flood control. These barriers have reduced the dolphins’ range by 80 percent and have divided them into small subpopulations. Given the small size of each subpopulation and their limited genetic diversity, their ability to persist in the long-term is in question.



The Indus River dolphin is one of the most threatened marine mammals in the world. Photo: from Secrets of the Blind Dolphins by Georgio Pilleri

In August 2010 there was a flood on the lower Indus River, which killed 1,700 people and damaged or destroyed 1.9 million homes. The barrage gates were opened for nearly two months to allow the flood waters to pass, giving the dolphins a rare opportunity to travel freely throughout the river and among the separate subpopulations. Marine mammal expert Dr. Gill Braulik, of the University of St. Andrews in the U.K., was eager to learn how the prolonged opening of the barrages had affected the dolphins’ distribution throughout the river. With funding from MCAF, Dr. Braulik teamed up with the Pakistan Wetlands Program to answer this question.

The Indus River: The system of barrages has severely fragmented the Indus River dolphin’s habitat.  Map: WWF  Map has been altered from original.



In the spring of 2011, Dr. Braulik and the Pakistani team traveled 1,000 miles of the Indus River, recording sightings of the dolphins, and comparing the data to previous studies. They learned that the dolphin populations were not greatly impacted by the flood, with one exception. They found a higher than normal number of dolphins downstream of the Sukkur barrage, an area that is mostly dry during the winter. Sadly, the dolphins that have traveled past the Sukkur barrage may be trapped in this marginal habitat, where they are unlikely to survive for more than a few months due to low dry season flows and intense fishing pressure. Unfortunately, the team learned that it is too dangerous to attempt a rescue of the dolphins from this area. Dr. Braulik and her team are now working to understand whether dolphins are continuing to migrate downstream into this unsuitable habitat, presenting a dangerous trend for this highly threatened species.

In addition to learning about this downstream migration, one of the other key outcomes of this project was building the capacity of the Pakistani researchers.

Members of the survey team. One of the key achievements of this project was training these local researchers in survey and data analysis techniques.  Photo: WWF-Pakistan


Gill Braulik trained the team in field survey techniques, use of GPS, safety and navigation, and data analysis. She notes:

More than 30 Pakistani researchers participated in the survey, [which] for many was their first opportunity to take part in this type of scientific study and large-scale expedition, to see the river in multiple different locations and to live on the river. This intensive exposure increased their understanding of the dolphin and the threats it faces immeasurably. Almost all participants have returned to their placements with greater knowledge about Indus dolphins, feeling part of a cohesive and supportive Pakistani dolphin conservation team, and more motivated and interested to pursue Indus dolphin conservation. Although the immediate impact of this on the dolphins is not possible to measure, I believe it is vitally important.

Although there are many threats facing these dolphins, it is a welcome and significant development to have local researchers trained and motivated to help this species survive.


References:

BRAULIK, G.T., BHATTI, Z.I., EHSAN, T., HUSSAIN, B., KHAN, A.R., KHAN, A., KHAN, U., KUNDI, K., RAJPUT, R., REICHERT, A.P., NORTHRIDGE, S.P., BHAAGAT, H.B. and GARSTANG, R. 2012. Robust abundance estimate for endangered river dolphin subspecies in South Asia. Endangered Species Research 17: 201-215.

Thursday, October 25, 2012

Check it out!: A firsthand look at the Giant Pacific Garbage Patch



Kim McCabe is a Visitor Education Specialist at the New England Aquarium. She is currently onexpedition in the mid-Pacific ocean studying plastic debris and its impact on the marine ecosystem. This is her introductory post as she heads out on expedition. Real time updates from this expedition will be posted on the Plastics At Sea: North Pacific Expedition website.




Take a look around you... Most of what we eat, drink and use is made of or packaged in plastic. This versatile, durable and inexpensive material has become an important part of our daily lives. Unfortunately, because of their over-use, improper disposal and slow degradation, plastics have also become a ubiquitous presence in the world’s oceans. [As previously reported in Aquarium blog entries from Fiji, the Bahamas and Indonesia.]

A piece of plastic floating through a coral reef in Raja Ampat, Indonesia (photo: Greg Stone)
Originally posted in this entry.

So is there really an island of trash--twice as big as Texas!--floating in the mid-Pacific gyre? Well... Turns out the term “garbage patch” is very misleading. A majority of the floating debris is smaller than your pinky nail and therefore can’t be seen from the deck of a moving ship [This post describes those small pieces of plastic as nurdles].

But just because the plastic pieces are small doesn’t mean it’s not a HUGE problem! What happens when marine life, from plankton to seabirds and whales, ingest these indigestible plastic morsels? How can we clean up our mess when it has incorporated itself into the planktonic community?

Currently, the extent of plastic debris in the oceans is poorly defined and more rigorous research is needed to define the scope of the problem, engage the public in conversation, and influence policy to find long-term solutions.

The RV Robert C. Seamans

This fall, I am joining a team of scientists, sailors, and concerned citizens on a research expedition into the “Giant Pacific Garbage Patch” to tackle tough questions about the impact of this long lived pollutant. We will spend 39 days sailing the Robert C. Seamans from San Diego to Honolulu collecting samples to determine not only how much plastic is polluting the Pacific, but also how it impacts marine life.

What are our objectives?
  • Estimate total plastic concentrations in the upper ocean using subsurface samples along with numerical modeling.
  • Investigate the community of microorganisms inhabiting the plastic debris (known as the “Plastisphere”).
  • Determine whether floating plastic acts as a vector for potentially invasive or pathogenic species to spread to new areas.
  • Survey for Japanese tsunami debris and predict its arrival on US shorelines.

Through these entries and outreach programs we will ensure that the outcomes of this expedition reach far beyond the deck of our ship!

Want to know more? Or are you just curious about what it’s like to live aboard a 135 foot sailing research vessel for 39 days without TV, internet or even a glimpse of land? Well, it turns out that bandwidth from the mid-Pacific ocean is limited and expensive, so I will not be posting from the boat, but I will be posting details here after I return.

In the meantime, John Waterman, journalist for National Geographic, and other crew members will be blogging thoughts, pictures, and videos throughout the expedition. I encourage you all to follow our voyage at the Plastics At Sea: North Pacific Expedition website.

Bon Voyage!
Kim McCabe

Wednesday, October 3, 2012

Belize: Reef Rollercoasters

Our trip has now come and gone, and we're done, now left to ponder all we've seen.

Large fans of black corals (Antipatharians) and the hedge-maze patterns of Mycetophyllia corals are still picturesque on deeper reefs.



The nice thing about a trip to Belize is that it is a place where I have been working for ~a decade now. It's my home reef—the reef that I know the best.


 Algae (mostly Dictyota) overgrowing much of the surface, prohibiting the growth of corals. 


A large number of algal-gardening damselfish have claimed the dead skeletons of once-dominant Acropora cervicornis (staghorn corals) for their homes.


Coral disease (here, black band... ) is still seen on the reefs.

Every day, we (literally) go up and down - our daily commuting dive from the surface to the reef. It's a bit of a rollercoaster, constantly scurrying to complete work before air or bottom time run out, then carefully ascending to the safety of the surface only to repeat the experience a few hours later.


But also some good news - fast growing thickets of Acropora palmata (elkhorn coral) are bursting in the shallows.

The physical rollercoaster is a typical part of the job, and we're all very used to it. But the ups and downs of reef status is a whole other kind of experience—elation with a healthy stand of large and thriving corals, sadness when a formerly coral reef is covered in algae. We see both the good and the sad here in Belize. While Pete measures fishes, it's my job to examine the corals and other benthic (bottom) dwellers and record their status (diversity, abundance, size, health) in each habitat.


Crinoids wave their golden arms from coral crevices.

The future of the reef is uncertain at this stage; all we know for sure is that the ride isn't over, and we're probably due for some more twists, turns, and loops. But I take heart in the healthy stands of large corals that we see in some areas, and hope that on the next trip we'll have more "ups" than "downs".

-Randi-

It's been quite an adventure! Don't miss a single animal sighting:

Monday, October 1, 2012

Belize: Noteworthy Sightings (From Pete)

As we survey the Belizean reefs it falls upon me to record the fish diversity and abundance.  While most of the time the usual suspects appear, we will upon occasion have some unusual sightings.


Goliath grouper

This trip we came across a beautiful, large Goliath grouper (Epinephelus itajara). This large fish allowed us to approach with a few feet, and made no indication of fleeing or backing away from our small group of divers. [Meet the Goliath groupers that live at the Aquarium here.]


Lionfish

Unfortunately we are seeing more and more lionfish (Volitans pterois).  These startlingly beautiful predators originally hail from the Indo-Pacific and have begun to colonize the Caribbean Sea and the East coast of the United States. [Aquarium divers have discussed the invasion of the lionfish here, here and taught students about this alarming situation here.] When we first began these transects in 2010 we saw one single lionfish in our survey of the reefs surround Carrie Bow and South Reef. Only two years later we have recorded many more sightings, often seeing a dozen or more on a single dive.


Loggerhead turtle

While certainly not a fish, we spied a large Loggerhead sea turtle (Caretta caretta) on one of our South Reef surveys.  This rather large reptile did not stay with us long, and headed out for deep water soon after we spotted it.

It was great to see such large and healthy fish on the reefs surrounding Carrie Bow Cay. We also noted several large black grouper, dog snapper and tiger grouper. Hopefully we will see more of these large fish as fishing pressure in the region is reduced. Unfortunately that is not a guarantee, and only time will reveal the effectiveness of the protected area.

- Pete