PAG the High Threat Sea: An Interview with Nora Al Mansoori about the Persian Arabian Gulf's aggressive conditions for survival of marine life
BY FARRAH LEONE
CORAL BLEACHING.
Okay, let me guess what places you just thought of. The Great Barrier Reef. The Bahamas. Polynesia. Micronesia. Hawai’i. Well, Noura Al Mansoori thinks of the Arabian Gulf aka the Persian-Asian Gulf (PAG).
Al Mansoori is a researcher at NYU Abu Dhabi who has studied a gamut of issues in the PAG, but for our interview we focused on her work with coral reefs and sea urchins. The Arabian Gulf is relatively shallow, which means it is susceptible to fast temperature change. In the summer, sea surface temperatures can range from 36/37 degrees Celcius but in the winter they can cool all the way “into the teens”. Not only do the temperatures change fast but it has an aggressively high salinity at about 45-50 parts per thousand whereas the Atlantic Ocean averages around 37 parts per thousand and the Pacific Ocean around 33-36 parts per thousand. The ability of life to survive there is astounding and Al Manoori aims to see how long that can last whether species are projected to “*adapt or **acclimate”.
*An adaptation is when an organism develops an inheritable trait.
**An acclimation is when an organism adjusts to an environment over the course of its life, not inheritable.
1. What has your work on coral bleaching and bioerosion taught us about adaptation vs. acclimation to climate change?
To start off, I’d like to explain bioerosion. In simple terms it is the biological erosion or removal and breakdown of geological materials through actions of living organisms and there are several ways bioerosion is performed; through chemical means (e.g., etching), mechanical means (e.g., abrasion), or by a combination of both mechanisms. When it comes to coral reef ecosystems, I learned that bioerosion is part of the balance that keeps an ecosystem more diverse and thriving, and if the balance is tipped where bioerosion processes are occurring faster and more than coral growth we start to see the ecosystem suffer. Exploring bioerosion started right after I learned about all the coral families and coral biology through our coral monitoring program and through coral cover analysis we started to see the demise of coral reefs across the southern basin of the Arabian Gulf, more particularly in the waters of Abu Dhabi. Through this program with the help of the Environment Agency Abu Dhabi, we managed to establish a good database that is still running, where we keep track of the coral cover and bleaching events across 9 important coral reef sites in the emirate of Abu Dhabi.
Through a study published by Dr. Emily Howells, we had an understanding of how fast the corals are growing here but we had no clue how fast they are being degraded. I started reading up on bioerosion more deeply and started talking to my supervisor and scientists in my team and during conferences about exploring this topic. We first started with what we had which were coral slices that were collected and photographed during the coral growth study and these images showed signs of macro-bioerosion. Through image analysis we were able to find the intensity of macrobioerosion that these corals went through at the time of their collection. This only gave us a snapshot of bioerosion intensity in the region and was an introduction to a more thorough study to asses the rates of bioerosion.
My colleagues here at NYU Abu Dhabi have found that in the Arabian Gulf and Sea of Oman, the corals can pass defensive adaptations to their offspring which could help protect them from rising sea temperatures. These findings provide hope for the future of coral reefs facing the devastating effects of climate change. Furthermore, the team of researchers at NYU Abu Dhabi and King Abdullah University of Science and Technology, in Saudi Arabia, studied types of reef-building corals that have adapted to the harsher waters of the Arabian Gulf and found that they can pass this resilience on to future generations.
These adaptations are passed down through epigenetics which are modifications that affect how often genes are used without actually changing the genetic code. This distinguishes epigenetic modifications from genetic adaptation, which is changes to the genetic code that take place over many generations.
According to Dr. Youssef Idaghdour, a professor of biology here at NYUAD, there is a surprising amount of potential for both male and female corals to transmit their epigenome (compounds that attach to DNA to change how they’re expressed without changing their DNA itself) to their offspring. Which showed the capacity of coral parents to positively impact the resilience of their offspring in environments that are changing too quickly.
With all the grim and rather bleak outlook for coral reefs in these climate extremes, the discovery from these researches has been giving us all a glimpse of hope.
2. Is there a specific reef or species in your area that you are concerned for?
We are all here concerned about Acropora spp., especially in the southern Arabian Gulf, stories from the elders in the region and even people who have been diving here in the past few decades say that the region was dominated by these table corals along most of the southern coastline, but the past decade more specifically has been showing a steep decline of Acropora cover and they have disappeared from certain sites, the only signs of their existence are the rubble they left behind along with a few live coral fragments hidden in-between the rubble.
The most pressing threats to coral reefs regionally and globally is climate change and most research estimate widespread loss of corals within the next century. Temperatures here go well beyond 35ºC, way over the survival limit of most species outside the Arabian Gulf. Scientists here and globally have started accepting that with the long generation times of corals , the rapid rate of climate change is outpacing the capacity for corals to genetically adapt to cope with rising temperatures
As we know, with every species in an ecosystem, there is something else that depends on it. Noura has also spent her time studying Sea Urchins of the PAG, that depend on reefs for nourishment.
3. Are you concerned for the survival of urchins?
In the Arabian Gulf it's hard to say just yet , but we have seen a rise in urchins as they are considered bioeroders, so the more corals are threatened the more food there is for these grazers. But we have also seen shallow rocky areas where usually urchins would be dominating to be empty and barren. Our speculations are that they also have a thermal threshold which we are exploring as well.
4. What would your response be to someone who is happy about degradation of urchin species because they want to save coral?
Ecosystems live in balance between growth and decay, especially coral reef ecosystems. These populations have numerous functional interactions among and between species which provide feedback that drive the pace and pattern of the overall dynamic and complex bioerosion process, and it also varies across reef zones, among coral habitats and over time . When it comes to urchin species and other organisms, there are many ways that bioeroder activity affect corals and coral reefs. For example carbonate excavation by bioeroding organisms creates and elaborates upon three dimensional habitat used by a wide range of reefal organisms. Invertebrates constitute a large component of reef communities and these cryptic populations occupy habitats provisioned by bioerosional activities. Sediments generated by bioerosinal processes contribute to reef cementation, produce lagoonal sediments and facilitate the recycling of carbonate materials . Bierosion is essentially a destructive process that weakens and fragments coral skeletons but also promotes asexual dispersal of coral colonies. However when the balance between accretion and bioerosion is tipped towards erosion, the development, maintenance and functioning of coral ecosystems is hindered. Understanding these basics is enough to make scientists explore and dive deeper into more complex questions which will help us better understand the more complex roles that bioeroders have.
Noura’s response here is beautifully written, but for the average joe, here’s what she is saying: Ecosystems are always in flux due to the wide variety of relationships they have whether it is with other organisms or with their physical environment. Sea Urchin bioerosion creates habitat on the reef for other species. The sediment that urchins leave behind helps to cement reefs and contributes to the different nutrient cycles of the environment. Bioerosion from urchins also promotes the asexual reproduction of coral colonies. In a world of coral bleaching, that is good because if no other complimentary organism is around, the coral can still propagate. Once this cycle is out of whack and leans towards too much erosion, is when we have a problem. But for now, we understand that their role in the ecosystem seems to balance out.
Photo by Noura Al Mansoori
5. Are you hopeful for the future of the PAG?
It’s hard to describe this feeling as hope, but it is some sort of hope that there will be some kind of inevitable habitat shift which we will have to live with and understand. I guess my main concern with all the destruction and degradation of the habitats we now have is that we do have a better understanding of the main causes of these shifts and even though some are not in our control, we know which ones are anthropogenic causes and what we need to do in order to slow down the climate change effects on these habitats.
6. What is one thing you want other researchers/scientists/conservationists to know about your research?
The Arabian Gulf is unique in the extremity of the sea temperatures, which can reach higher than 36°C in the summer. The corals here are especially interesting to researchers who use the findings to hypothesise how corals in other parts of the world will cope with rising sea temperatures in the future. A 2018 study that we published with the Environment Agency in Abu Dhabi has shown that almost three-quarters of the coral reefs here have been bleached. In order to understand these patterns, more collaborative work needs to be encouraged and followed through in order to tie things together and help us find solutions.
7. How can people get involved with your work? (i.e. petition, gofundme, groups to join/follow, etc)
Lab page with PI and researchers profiles and contact
Instagram page : @nyuad.marinebiology
Facebook page : https://www.facebook.com/NYUADmarinebiologylab
Nouras instagram handle : @noura.almn
