Thursday, January 30, 2014

A trip to the Red Sea, Rabigh Lagoon

January 2014: Rabigh and Jeddah, Saudi Arabia

I traveled to the west coast of Saudi Arabia at the invitation of Dean Mohammed Al-Jahdali (a marine biologist) to start a collaboration between biologists at King Abdulaziz University – Rabigh Campus and FIU’s Marine Science Program.  We are working to develop a project to restore and study Rabigh Lagoon and the surrounding waters of the Red Sea.

After a long but pleasant couple of flights, I arrived in Jeddah in the middle of a sandstorm (luckily it was nice enough as we flew over the Red Sea on the Egyptian side to have a great view of the desert and coast).   

The Egyptian coast of the Red Sea.



It’s the first time I’ve been in a sandstorm, but I am told that they are very uncommon in this area! Needless to say with the high winds and flying sand I was a bit concerned about getting out on the water eventually!  The drive north from Jeddah to the small city of Rabigh lasted about an hour and a half and was through pretty much constant wind and sand. I am very glad I didn’t have to drive! 



The pictures just don't seem to show just how windy and
sandy it was!
































I spent the first day and a half talking to the scientists at KAU and touring their new campus and the city.  We had some amazing meals including fresh local seafood.  By the time we headed out to the lagoon I was really excited to see – and swim in – the Red Sea.   The trip was awesome.  We drove across hard-packed sand roads and encountered a large group of wild camels feeding along the shores of the lagoon early in the morning.  Once we left them, we drove along the shore of the lagoon and saw the roads that had blocked much of the flow of water from the lagoon to the Red Sea – forcing it through a single narrow pass until the government removed one of the roads just a few months ago.  Still, it looks like a couple of bridges to replace the roads with a couple pipes running through them would help the lagoon tremendously.



Road blocking natural flow to and from the lagoon

Pipes under the road don't let enough water through


Based on a quick look around, there is no question that the lagoon could use some restoration work.  Although the corals, seagrass and mangroves near the mouth of the lagoon that has always been open look pretty good, those farther away are not faring as well.  Still, there is a good amount of live coral and with the newly opened waterway, there is a good chance for restoration to make a big difference while Dean Mohammed works to have more flow restored to the bay.  
Heading out onto the lagoon

Seagrass in the lagoon covered by sediment


Coral and sponge inside the lagoon

Mangroves provide important nursery habitat for fish



Towards the end of our tour we had a chance to quickly poke the boat out to the reef that lies along the open coastline.  We just went a few hundred meters offshore to the reef crest and I jumpped in.  It took my breath away.  The amount of living coral, the colors, and the huge abundance of fish was maybe the best I have ever seen!  Of course, Dean Mohammed said it was like watching black and white TV compared to other areas down the coastline a ways.  I can’t imagine what that would be like!  Eventually, I was coaxed back into the boat to head back to campus to discuss the project.  I am pretty excited about the potential for a team to do an incredible marine restoration project as well as some amazing science in a beautiful area. 

The reefs outside the lagoon were covered in living corals and fish.






Tuesday, December 3, 2013

Dr. Adam Barnett's visit and sevengill sharks

3 December 2013

A couple weeks ago, we had the pleasure of welcoming Dr. Adam Barnett to the lab for more than a week.  Adam has been doing some really interesting work on sevengill and tiger sharks, and hopefully we can get some projects going together soon!  He also has been working on a great website with lots of information.  Check it out at http://www.oceansiq.com!

I'll turn it over to him for a brief update of what he's been up to!




Among other projects, I have been working on sevengill sharks Notorynchus cepedianus in the temperate waters of south-east Australia and South Africa, and tiger sharks Galeocerdo cuvier in north-east Australia (see our research projects at oceansiq.com), effectively studying two important apex predators in the two differing systems. The sevengill shark work in Tasmania Australia has been quite comprehensive, using a range of methods to show their habitat use patterns and the important role they play in coastal ecosystems. The study in South Africa has only recently begun and our focus site is False Bay, where we will also be identifying habitat use, the importance of the aggregation site in False Bay and the sevengill sharks’ role in the ecosystem. We will also examine if this role varies when they share the coastal system with white sharks Carcharodon carcharias. White sharks and sevengill sharks are widely distributed in temperate waters around the world, and these two co-occurring apex predators consume the same prey (e.g. fur seals and other sharks). Adult sevengill sharks (up to 3 metres in length) in coastal systems generally have little threat of predation, and any predation would be expected to come from the larger white sharks (up to 6 m). Despite this overlap in distribution and prey consumption, the relationship (if any) between these two apex predators is unknown. The work in South Africa will also provide the chance for cross regional comparisons in sevengill shark ecology.

To date, our tiger shark work has focused on the movement patterns of this species at Raine Island, the largest green turtle nesting site in the world. 


     A diver coming face to face with a sevengill shark at the aggregation site in False Bay, South Africa (photo credit Morne Hardenberg)

Taking blood from a sevengill alongside the boat (Photo Alison Kock)

Underwater view of sevengill restrained alongside boat (Photo Adrian Hewitt)

How many sharks visit the Moorea ray feeding site?


3 December 2013

Data analysis is ongoing...and there is a lot to do going through all the video and preparing the samples for stable isotope analysis.   Johann just finished processing the photos that were taken of blacktip reef sharks at the shallow water site.  Because each shark has unique markings on their fins, we can see how many individuals were observed at the site and how often they are there.    During eight photography sessions lasting between 15 and 40 min, Johann identified 64 different blacktip reef sharks (33 females and 31 males) with a mximum of 47 sharks during 1 session!

Now, we are going through the data from the drone to see if the counts we get from the air are similar to those made using photoidentification.
The ray feeding site inside the reef tract.