Please select your home edition
Edition
Wildwind 2016 728x90

Where in the world are our strongest corals?

by Hanny Rivera - Cohen's Lab on 22 Aug 2014
Seventy Islands, Palau - One of several Rock Islands chains in Palau Cohen's Lab
The Palauan archipelago is a composed of more than 250 islands. Among these are about 200 known as the Rock Islands, due their tough limestone composition. These islands form a series of semi enclosed bays south of Palau's most populated island, Koror. These bays are thriving with wildlife and the coral cover and diversity is spectacular, especially when considering the environmental conditions in these areas.

Reef-building corals, build make their skeleton from calcium carbonate (limestone), specifically the aragonite mineral form of calcium carbonate. How difficult it is for them to make aragonite is largely dependent on a quantity called the aragonite saturation, which essentially corresponds to how favorably this mineral can form under the current conditions and is very sensitive to the pH of the water.

Decades of research on coral health and optimal conditions for coral growth indicate that corals can make their skeletons more easily and more quickly when the pH is more basic as opposed to more acidic, or correspondingly when the aragonite saturation is higher. The relationship between coral growth and pH is particularly relevant in the context of global climate change and rising atmospheric concentrations of CO2 - as CO2 concentrations in the atmosphere increase, more CO2 becomes dissolved in the oceans, a process that decreases the pH of the water (commonly referred to as ocean acidification), and decreases the aragonite saturation. Combined with other stressors such as increased temperatures, increased pollution and nutrient input, impacts from overfishing and coastal developments, corals face an increasing number of threats.


In Palau's Rock Islands, the pH and the aragonite saturation is much lower than in the surrounding outer reefs, however, the corals in these bays show no reduction in growth despite living in conditions we would normally deems stressful for their growth. Our lab made this discovery a few years ago and has been studying the corals in these bays ever since, trying to understand just how they are able to defy our expectations. Why can they thrive under these conditions? Have they always been able to do so? Are the populations in these bays different from those in other regions of Palau? Is there genetic exchange between these resistant corals and other populations in Palau's outer reefs and beyond?

In our current expedition will have a rare opportunity to reach some of the islands farthest from Palau's mainland, such as Helen Reef, the southernmost of Palau's reefs and Kayangel, the northern most. We will characterize environmental conditions at these new sites - for instance, are there other low pH sites we've yet to uncover? Furthermore, we also want to study connectivity between different areas of Palau. By taking tissue samples from corals at multiple locations, we can use genetic techniques to study gene flow between different regions, this can tell us if corals in a particular environment, such as the low pH Rock Islands, are genetically isolated from other populations and have perhaps adapted to these conditions over time. If they are not isolated, it can tell us where these resistant populations could have dispersed to in the past, indicating those areas may show resistance when conditions become stressful in the future. Knowledge that is very important in making adequate management decisions.

We will tour Palau for almost three weeks, stopping at fifteen sites. We are quite fortunate to have use of the vessel M/V Alucia, for our work during this expedition, without which access to the farther reefs like Helen and Kayangel would have been unfeasible.

Anchors away.

Merand is the Palauan word for coral. The Cohen's Lab current expedition to Palau seeks to understand why some
of Palau's coral can thrive in low pH conditions.


For more info, click here

Colligo Marine 660x82upffront 660x82Schaefer 2016 Ratchet Block 660x82

Related Articles

Zhik sailors win 17 sailing medals at 2016 Olympic Regatta
The 2016 Olympic games are over and what a Games they have been - Zhik sailors dominated Zhik sailors won almost 60% of the medals contested at Rio de Janeiro. It was a regatta which tested sailors and gear - with one day being the most severe conditions ever experienced at an Olympic regatta. For the Zhik team riders on the waters of Rio, four years and more of hard work and dedication have paid off for many.
Posted on 29 Aug
PredictWind - One stop shop
PredictWind have taken the bold step of adding government provided forecasts to their award winning forecasting software PredictWind the world leader in forecasting believe that more is better, and have taken the bold step of adding government provided forecasts to their award winning forecasting software.
Posted on 15 Aug
Marine Resources job updates
Marine Resources specialises in providing expert recruitment services to the leisure marine industry worldwide. Marine Resources specialises in providing expert recruitment services to the leisure marine industry worldwide. Jobseekers register your CV now to receive the latest vacancies and be matched to your ideal job. Employers choose from a variety of recruitment options which include a full consultancy service as well as a unique job advertising package.
Posted on 11 Aug
America's Cup - Southern Spars to build AC50 for Emirates Team NZ
Southern Spars has been appointed to build Emirates Team New Zealand’s AC50 wingsailed foiling catamaran One of the world's leading composite engineering companies, Southern Spars has been appointed to build Emirates Team New Zealand’s AC50 wingsailed foiling catamaran for the 35th America’s Cup campaign. The move marks a shift away from Cookson Boats who have been Team New Zealand's boatbuilder since 2000. No reasons have been given for the decision to change the builder.
Posted on 24 Jul
Upffront.com - Tuff Luff and Harken Headfoils
Upffront.com is a comprehensive online purchasing platform for performance sailing hardware and rigging systems Upffront.com is a comprehensive online purchasing platform for performance sailing hardware and rigging systems; orders are processed 24 hours a day, 365 days a year and we deliver to customers located anywhere in the world.
Posted on 8 Jul
Barz floating sunglasses - Ideal for sailing in rough conditions
Our SAN JUAN floating model fitted with 1.1mm Acetate Lenses have a density of 0.95 GM/ML Barz floating sunglasses float in rough conditions. Most sunglasses that say they float, only float in the bathtub as once they break surface tension (or if there is any movement on top of the water)... down they go...
Posted on 7 Jul
Free $US3,000 Carbon Vang with SouthernFurl boom orders in July
Southern Spars is giving a free carbon vang - valued at US$3,000 - with SouthernFurl in-boom furlers ordered in July Southern Spars is giving away a free carbon vang - valued at US$3,000 - with all of their SouthernFurl in-boom furlers ordered in July. Carbon gas vangs make a great addition to the furling boom package, though if you’d prefer to keep your existing one, Southern Spars will offer you a 5% discount on the price of your boom instead.
Posted on 29 Jun
11th Hour Racing to present at annual Green Sports Alliance Summit
11th Hour Racing is headed to Houston, Texas, to present at the annual Green Sports Alliance Summit 11th Hour Racing is headed to Houston, Texas, to present at the annual Green Sports Alliance Summit, June 28-30, the world’s largest gathering for the sports community around sustainability, including both professional and collegiate sports teams, leagues and venues.
Posted on 25 Jun
PredictWind - Stunning new forecast maps
When developing the Offshore App, we had to rethink maps for offshore sailors. When developing the Offshore App, we had to rethink maps for offshore sailors. The mapping technology was rebuilt to be faster, have smaller downloads and be able to smoothly animate PredictWind’s advanced forecasts. Following the success of the Offshore App, we’re releasing this unique display technology across all other platforms, including the forecast website, Android and iOS Apps
Posted on 24 Jun
Extreme Sailing Series™ partners with Cisco Systems
The global technology company will provide exclusive networking solutions that will transform wireless connectivity The first venue at which members of the public, race officials and sailors will benefit from the Cisco WiFi solutions will be Cardiff – the third Act of the 2016 season – where the action gets underway on the water on 23 June. As an Official Series Supplier, Cisco will provide similar facilities at the remaining Acts of 2016.
Posted on 22 Jun