Archive for Friday, 4 March 2016

NOAA Scientist Helps Make Mapping Vital Seagrass Habitat Easier and More Accurate 

Shoal grass seagrass on a sandy ocean floor.

Seagrass beds serve as important habitat for a variety of marine life, and understanding their growth patterns better can help fisheries management and restoration efforts. (NOAA)

MARCH 3, 2016 — Amy Uhrin was sensing a challenge ahead of her.

As a NOAA scientist working on her PhD, she was studying the way seagrasses grow in different patterns along the coast, and she knew that these underwater plants don’t always create lush, unbroken lawns beneath the water’s surface.

Where she was working, off the North Carolina coast near the Outer Banks, things like the churning motion of waves and the speed of tides can cause seagrass beds to grow in patchy formations.

Clusters of bigger patches of seagrass here, some clusters of smaller patches over there. Round patches here, elongated patches over there.

Uhrin wanted to be able to look at aerial images showing large swaths of seagrass habitat and measure how much was actually seagrass, rather than bare sand on the bottom of the estuary. Unfortunately, traditional methods for doing this were tedious and tended to produce rather rough estimates. These involved viewing high-resolution aerial photographs, taken from fixed-wing planes, on a computer monitor and having a person digitally draw lines around the approximate edges of seagrass beds.

While that can be fairly accurate for continuous seagrass beds, it becomes more problematic for areas with lots of small patches of seagrass included inside a single boundary. For the patchy seagrass beds Uhrin was interested in, these visual methods tended to overestimate the actual area of seagrass by 70% to more than 1,500%. There had to be a better way.

Seeing the Light

Patches of seagrass beds of different sizes visible from the air.

Due to local environmental conditions, some coastal areas are more likely to produce patchy patterns in seagrass, rather than large beds with continuous cover. (NOAA)

At the time, Uhrin was taking a class on remote sensing technology, which uses airborne—or, in the case of satellites, space-borne—sensors to gather information about the Earth’s surface (includinginformation about oil spills). She knew that the imagery gathered from satellites (i.e. Landsat) is usually not at a fine enough resolution to view the details of the seagrass beds she was studying. Each pixel on Landsat images is 30 meters by 30 meters, while the aerial photography gathered from low-flying planes often delivered resolution of less than a meter (a little over three feet).

Uhrin wondered if she could apply to the aerial photographs some of the semi-automated classification tools from imagery visualization and analysis programs which are typically used with satellite imagery. She decided to give it a try.

First, she obtained aerial photographs taken of six sites in the shallow coastal waters of North Carolina’s Albemarle-Pamlico Estuary System. Using a GIS program, she drew boundaries (called “polygons”) around groups of seagrass patches to the best of her ability but in the usual fashion, which includes a lot of unvegetated seabed interspersed among seagrass patches.

Six aerial photographs of seagrass habitat off the North Carolina coast, with yellow boundary lines drawn around general areas of seagrass habitat.

Aerial photographs show varying patterns of seagrass growth at six study sites off the North Carolina coast. The yellow line shows the digitally drawn boundaries around seagrass and how much of that area is unvegetated for patchy seagrass habitat. (North Carolina Department of Transportation)

Next, Uhrin isolated those polygons of seagrass beds and deleted everything else in each image except the polygon. This created a smaller, easier-to-scan area for the imagery visualization program to analyze. Then, she “trained” the program to recognize what was seagrass vs. sand, based on spectral information available in the aerial photographs.

Though limited compared to what is available from satellite sensors, aerial photographs contain red, blue, and green wavelengths of light in the visible spectrum. Because plants absorb red and blue light and reflect green light (giving them their characteristic green appearance), Uhrin could train the computer program to classify as seagrass the patches where green light was reflected.

Classify in the Sky

Amy Uhrin stands in shallow water documenting data about seagrass inside a square frame of PVC pipe.

NOAA scientist Amy Uhrin found a more accurate and efficient approach to measuring how much area was actually seagrass, rather than bare sand, in aerial images of coastal North Carolina. (NOAA)

To Uhrin’s excitement, the technique worked well, allowing her to accurately identify and map smaller patches of seagrass and export those maps to another computer program where she could precisely measure the distance between patches and determine the size, number, and orientation of seagrass patches in a given area.

“This now allows you to calculate how much of the polygon is actually seagrass vegetation,” said Uhrin, “which is good for fisheries management.”

The young of many commercially important species, such as blue crabs, clams, and flounder, live in seagrass beds and actively use the plants. Young scallops, for example, cling to the blades of seagrass before sliding off and burrowing into the sediment as adults.

In addition, being able to better characterize the patterns of seagrass habitat could come in handy during coastal restoration planning and assessment. Due to local environmental conditions, some areas are more likely to produce patchy patterns in seagrass. As a result, efforts to restore seagrass habitat should aim for restoring not just cover but also the original spatial arrangement of the beds.

And, as Uhrin noted, having this information can “help address seagrass resilience in future climate change scenarios and altered hurricane regimes, as patchy seagrass areas are known to be more susceptible to storms than continuous meadows.”

The results of this study, which was done in concert with a colleague at the University of Wisconsin-Madison, have been published in the journal Estuarine, Coastal and Shelf Science.

Source: NOAA Scientist Helps Make Mapping Vital Seagrass Habitat Easier and More Accurate |

Sharks and Rays Without Borders

Sharks and Rays Without Borders

Although several countries have protections for sharks and rays in place, many species travel great distances, often crossing national boundaries. Their migratory routes are determined by nature, not by the borders we’ve drawn. International cooperation is vital to ensuring the survival of these exceptionally vulnerable migratory species. The Convention on Migratory Species (CMS) – a global wildlife treaty with 120 Parties — is uniquely suited to facilitate such action.


In November 2014 in Quito, Ecuador, CMS Parties (member countries) from all over the world debated and decided on an unprecedented number of proposals that could greatly improve the outlook for 21 species of imperiled sharks and rays. Project AWARE was there to represent the voice of the dive community and to work with partner NGOs to urge the CMS Parties to commit to regional protections for the proposed shark and ray species. Such actions bring responsibilities for member countries to work nationally and regionally to safeguard listed species and ensure the health of their habitats throughout migratory pathways.

 Project AWARE CMS campaign #SharksWithoutBorders

Send a letter – Our letter campaign direct to delegates is now closed. Thank you to everyone involved. 28,804 letters were delivered to decision-makers urging them to support the shark and ray proposals.

Thunderclap – On 4th November, 632 people with a social media reach of almost 550k sent a loud unified message #SharksWithoutBorders.

Your support made a difference for:

  • All five sawfishes, nine devil rays, and the reef manta – proposed for CMS Appendix I & II. Appendix I is reserved for migratory species that are threatened with extinction and brings an obligation for CMS Parties to strictly protect these animals, restore their habitats, and mitigate obstacles to migration.

  • Two species of hammerheads, all three threshers, and the silky shark – proposed for CMS Appendix II, which encourages regional cooperative initiatives to conserve shared populations.

  • Threats to their migration routes and habitat, including marine debris. Our trash underwater harms marine animals, entangles sharks and rays, and damages critical marine environments. Much like migratory animals, marine debris crosses political boundaries, moving from one territorial sea to the open ocean and ending up in another nation’s waters. As a multilateral environmental agreement, CMS can also address this issue, and thereby further improve the outlook for marine species.

Fact sheets on the newly listed species and how the listings might help them can be found here.

22 Shark and Ray Species Added to Scope of Global Agreement

22 Shark and Ray Species Added to Scope of Global Agreement

Signatories to the Convention on Migratory Species (CMS) Memorandum of Understanding (MoU) for Sharks have unanimously agreed to add twenty-two species of sharks and rays to the MoU scope, and to accept the applications of six conservation groups as Cooperating Partners in fulfilling MoU objectives. Conservationists are, in turn, calling on countries to take concrete national and international actions to fulfill new commitments to the imperiled species.

Conserving Migratory Sharks & Rays: Priorities for Action Governments gathering to discuss the next steps in implementing the Convention on Migratory Species (CMS) Memorandum of Understanding (MoU) for Sharks have an important opportunity to make real progress in addressing the global plight of sharks and rays, particularly the 29 species currently listed on the CMS Appendices. Beyond adding species and working groups to the CMS MoU scope of work, there are multiple avenues for immediate, concrete action that can go a long way toward fulfilling CMS obligations for listed species, as well as broader commitments to cooperate toward better protection for these vulnerable animals. Our organizations welcomed the 2010 CMS MoU for the seven shark species listed between 1999 and 2008, participated in development of the 2012 Conservation Plan to promote MoU objectives, and celebrated the historic listing of 21 additional species (15 rays on Appendix I & II and six sharks on Appendix II) in 2014. Through the CMS Sharks MoU and Conservation Plan, signatories have agreed, inter alia, to: § facilitate a better understanding of shark populations and fisheries § set science-based catch limits in an effort to ensure sustainable fishing § prevent “finning” (slicing off a shark’s fins and discarding the body at sea) § cooperate toward shark conservation through international bodies, and § protect critical shark habitats. Shark species covered by the CMS Sharks MoU, after listings from 1999 to 2008: § Whale shark (Rhincodon typus) § White shark (Carcharodon carcharias) § Basking shark (Cetorhinus maximus) § Porbeagle (Lamna nasus) § Spiny dogfish (Squalus acanthias) § Shortfin mako (Isurus oxyrinchus) § Longfin mako (Isurus paucus) Shark & ray species listed in 2011 & 2014, not yet covered by the Sharks MoU: § All five species of sawfish (Family Pristidae) § All nine species of devil rays (Mobula spp.) § Both manta rays (Manta spp.) § All three thresher sharks (Alopias spp.) § Great hammerhead (Sphyrna mokarran) § Scalloped hammerhead (Sphyrna lewini) § Silky shark (Carcharhinus falciformis) CMS w 2NDMEETING OF SIGNATORIES TO THE SHARKS MOU w FEBRUARY 2016 As the first intergovernmental treaty dedicated to global shark conservation, the CMS MoU has bolstered efforts to safeguard these vulnerable species, through both awareness and action. Listings on the Appendices, in particular, have been a major factor in numerous domestic protections while also serving to highlight at-risk species for other international fora. Nearly four years after adoption of the Conservation Plan, however, concrete actions to fulfill MoU goals remain insufficient. For example, the following are regrettable: § The lack of species-specific regional plans for listed shark species, even the first to be listed (whale sharks) § The absence of Regional Fishery Management Organization (RFMO) catch limits for shortfin mako sharks § The repeated defeat of US and EU proposals to cap shortfin mako landings through ICCAT1 § Exceptions to the protections for manta and devil ray (mobulids) adopted last year by the IATTC2 § Continued fishing and lack of national protections for mobulid rays, particularly Mobula species § Weak national and international finning bans that rely on complicated fin-to-body ratios for enforcement § Little cooperation among countries aiming to recover shared porbeagle and spiny dogfish populations § The small proportion of Signatories submitting national reports. In addition to expanding the MoU’s scope to cover all shark and ray species listed on the CMS Appendices (adding the 22 species listed in 2011 and 2014 to MoU Annex I), and in line with appropriate amendments to the Conservation Plan (MoU Annex 3), associated work program, priorities and strategy, we urge CMS Parties and Non-Party Signatories to take the following concrete steps: § Ensure strict national protection for all Appendix I listed species, especially those listed by IUCN as Endangered or Critically Endangered (all sawfish in Family Pristidae and giant devil ray Mobula mobular) § Co-sponsor and actively promote EU/US-led efforts to establish shortfin mako catch limits under ICCAT § Develop and promote proposals to establish shortfin mako catch limits at other relevant RFMOs § Seek to end exceptions to the mobulid ray protections adopted in 2015 by IATTC § Develop and promote proposals to protect mobulid rays through other relevant RFMOs § Support proposals to list mobula rays, thresher sharks, and silky sharks under CITES3 Appendix II § Ensure national finning bans include best practice prohibitions on at-sea fin removal, without exception § Co-sponsor EU/US-led proposals to strengthen RFMO finning bans by prohibiting at-sea fin removal § Establish active inter-sessional working groups to focus on specific regional conservation priorities § Encourage neighboring countries to sign the Sharks MoU § Complete and submit in a timely manner national progress reports to the CMS Secretariat § Consider proposing to list depleted angel sharks and guitarfishes as well as heavily fished blue sharks. Our organizations are grateful for the opportunity to collaborate with Signatories as Cooperating Partners under the MoU. Through actions like those urged above, we can ensure a brighter future for sharks and rays. Shark Advocates International is a project of The Ocean Foundation working to safeguard sharks and rays through sound, science-based conservation policy. Supporting work in more than 35 countries, Humane Society International is one of the only international organizations working to protect all animals. The Shark Trust is a UK charity working to advance the worldwide conservation of sharks through science, education, influence and action. Project AWARE Foundation is a growing movement of scuba divers protecting the ocean planet – one dive at a time. Defenders of Wildlife is dedicated to the protection of all native animals and plants in their natural communities

New commitments and partners agreed by Signatories to Convention on Migratory Species Shark MoU

The CMS 2010 Shark MoU is the first global instrument dedicated to the conservation of migratory sharks and rays. The addition of 22 species (listed on the CMS Appendices in 2011 and 2014) brings the total number of species under the MoU’s scope to 29: white shark, porbeagle, spiny dogfish, basking shark, both makos, all three threshers, two species of hammerheads, whale shark, all nine devil rays, both mantas, all five sawfishes, and the silky shark. The number of MoU Signatories rose to 40 (39 national governments and the EU) with this week’s addition of Portugal.

“We are encouraged by the growing number of countries that are engaging in CMS shark and ray conservation activities, and welcome the expansion of the Shark MoU scope,” said Sonja Fordham of Shark Advocates International. “At the same time, we are eager for countries to follow up with concrete actions in line with these commitments, particularly strict protections for highly threatened rays, and fishing limits to ensure the long-term health of migratory shark populations.”

Through the CMS Shark MoU and associated Conservation Plan, signatories have agreed to facilitate a better understanding of shark populations and fisheries, set science-based catch limits, prevent “finning” (slicing off a shark’s fins and discarding the body at sea), protect critical shark habitats, and cooperate toward shark conservation through international fisheries and wildlife bodies. Shark Advocates International, Shark Trust, and Project AWARE were among the conservation groups accepted as Cooperating Partners in fulfilling Sharks MoU objectives.

“Our organizations are honored by the opportunity to serve as Cooperating Partners and thereby collaborate toward migratory shark and ray conservation with countries at the forefront of this critical work,” said Ali Hood, Director of Conservation for the Shark Trust. “This status gives us a special opportunity to share expertise and provide support while ensuring implementation of the associated Conservation Plan.”

CMS Parties are obligated to strictly protect the manta and devil rays and the five sawfishes (through listing on CMS Appendix I), and to work internationally to conserve the sharks listed on Appendix II.

“We applaud Costa Rica for hosting this important and successful meeting, and for the country’s past initiatives to secure international trade controls on hammerheads and to strengthen shark finning bans on a global scale,” said Ania Budziak, Associate Director for Project AWARE. “We are hopeful that new commitments made this week will lead to strict national protections for devil rays and sawfishes, and the end of Costa Rican opposition to regional fishing limits for hammerhead and silky sharks.”

Source: 22 Shark and Ray Species Added to Scope of Global Agreement

%d bloggers like this: