Biodiversity Helps Coral Reefs Thrive – And Could Be Part Of Strategies To Save Them

Biodiversity Helps Coral Reefs Thrive – And Could Be Part Of Strategies To Save Them A healthy coral reef at Swains island, American Samoa. NOAA/NMFS/PIFSC/CRED, Oceanography Team., CC BY

Coral reefs are home to so many species that they often are called “the rainforests of the seas.” Today they face a daunting range of threats, including ocean warming and acidification, overfishing and pollution. Worldwide, more than one-third of all coral species are at risk of extinction.

I am one of many scientists who are studying corals to find ways of helping them survive and recover. As a recent report from the National Academies of Science, Engineering and Medicine shows, researchers are exploring many different strategies. Some, such as managed breeding to make corals more tolerant of stresses, are already being developed at small scales. Others, such as moving corals to colonize new areas, have not been tested yet.

My own work examines whether greater diversity of coral species on reefs can help corals survive and thrive. In a study published earlier this year, my colleague Mark Hay and I found evidence that the answer is yes. This finding could help to inform broader strategies for making coral reefs more resilient in altered oceans.

In nature, more is better

Are ecosystems healthier if they contain many species than if they harbor only a few? This is a central question in ecology. Generally, scientists have found that ecosystems with more diverse foundation species – those that define a system and are inseparable from it, such as trees in a forest – tend to be healthier and function better.

Until recently, no one had applied this test to coral reefs. But we do know that healthy coral reefs are diverse, structurally complex ecosystems dominated by corals. In contrast, reefs that have been damaged by stresses such as coral bleaching events tend to become simplified, less diverse landscapes, often dominated by seaweeds.

For our study we chose a reef area on the southwestern coast of Fiji’s main island, Viti Levu, in the South Pacific. Many reefs along this coast have been heavily degraded by overfishing and other human-related activities, reducing coral cover and allowing seaweeds to dominate.

There are hundreds of coral species across the Pacific, but at smaller scales, we found just five species or fewer during preliminary surveys conducted on the degraded reef at our site. Since these conditions mirror what is happening to many reefs worldwide, we saw it as an ideal place to test whether coral diversity matters for the “new normal” that we expect to see on reefs of the future.

Coral reefs stressed by overfishing can rapidly become dominated by seaweeds. Some types of seaweed produce chemicals that repel coral and fish larvae, which may prevent degraded reefs from recovering.

Underwater gardens

Our team created 48 concrete plots on the seafloor of the degraded reef, which served as the bases for experimental coral gardens. We created single-species gardens that each contained one of three coral species – Pocillopora damicornis, commonly known as cauliflower coral; Porites cylindrica, also known as yellow finger coral; and Acropora millepora, one of a number species known as staghorn corals. We also planted mixed gardens containing all three species.

Biodiversity Helps Coral Reefs Thrive – And Could Be Part Of Strategies To Save ThemWe chose these corals because they are common to reefs across the Pacific and are representative of different coral families that have shown varying responses to a variety of harmful disturbances. In all, each garden contained 18 coral individuals, for a total of 864 corals.

 A Porites cylindrica coral planted in our experimental gardens. Each coral was embedded within an upside-down soda bottle neck using epoxy, which allowed us to easily attach or remove them from the garden plots. Cody Clements, CC BY-ND

To assess each coral’s performance as it grew, we needed to remove them from their plots periodically. So we cut off the tops of hundreds of soda bottles and planted an individual coral in the upside-down neck of each bottle with epoxy putty. We embedded the bottle caps into our concrete slabs so that we could easily unscrew each bottle neck to examine the coral it held, then screw it back into its base. Over 16 months we weighed the corals and tracked other measures of their well-being, including tissue death and colonization of each garden by harmful seaweeds.

Biodiversity Helps Coral Reefs Thrive – And Could Be Part Of Strategies To Save Them Experimental coral gardens on a degraded reef in Fiji. Gardens with a mix of coral species performed better than gardens containing only one species. Cody Clements, CC BY-ND

We consistently found that corals grown in mixed-species gardens performed better than those in single-species plots. Within four months, coral growth in the mixed-species gardens was even exceeding the best-performing single-species gardens. This suggests that different species may benefit each other in yet unknown ways, at least during early stages of a coral community’s development.

Biodiversity Helps Coral Reefs Thrive – And Could Be Part Of Strategies To Save Them Examples of single- and mixed-species coral gardens through time during our 16-month experiment. At four months, mixed-species gardens were outperforming single-species gardens in multiple ways – growing faster on average than even the best performing single-species gardens (Acropora millepora). By 16 months, growth was comparable between mixed-species and Acropora gardens, but aggregate performance of single-species gardens continued to lag behind their mix-species counterparts. Clements and Hay, 2019, CC BY-ND

Why is more better?

The next question is what drove the effects that we observed. We hope to investigate a number of leads in future experiments. For example, farmers commonly observe that planting a diverse mix of crops helps to reduce the spread of infectious diseases among individuals. Could the same be true for coral reefs?

Our initial findings offer both concern and hope for the future of coral reefs. If diversity is integral to coral well-being, then continued species loss could dramatically alter these ecosystems in ways that lead to further reef decline. How many parts can be removed from the “ecosystem engine” before it breaks down?

That said, many of the strategies in the National Academies report involve using biodiversity – both at the genetic and species level – to enhance coral reef resilience. Examples include cross-breeding corals between populations; altering coral genes to give them new functions, such as higher heat tolerance; and moving stress-tolerant corals or coral genes to new locations.

Promising advances in technology, such as mapping coral reefs from the air, may also help researchers assess coral health and determine which species they contain. This baseline information may help better inform management and restoration efforts.

Corals are in trouble, but they aren’t down for the count yet. Perhaps harnessing the power of their remaining biodiversity can help give them a fighting chance.

About The Author

Cody Clements, Postdoctoral Fellow, Georgia Institute of Technology

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Related Books

Climate Adaptation Finance and Investment in California

by Jesse M. Keenan
0367026074This book serves as a guide for local governments and private enterprises as they navigate the unchartered waters of investing in climate change adaptation and resilience. This book serves not only as a resource guide for identifying potential funding sources but also as a roadmap for asset management and public finance processes. It highlights practical synergies between funding mechanisms, as well as the conflicts that may arise between varying interests and strategies. While the main focus of this work is on the State of California, this book offers broader insights for how states, local governments and private enterprises can take those critical first steps in investing in society’s collective adaptation to climate change. Available On Amazon

Nature-Based Solutions to Climate Change Adaptation in Urban Areas: Linkages between Science, Policy and Practice

by Nadja Kabisch, Horst Korn, Jutta Stadler, Aletta Bonn
3030104176
This open access book brings together research findings and experiences from science, policy and practice to highlight and debate the importance of nature-based solutions to climate change adaptation in urban areas. Emphasis is given to the potential of nature-based approaches to create multiple-benefits for society.

The expert contributions present recommendations for creating synergies between ongoing policy processes, scientific programmes and practical implementation of climate change and nature conservation measures in global urban areas. Available On Amazon

A Critical Approach to Climate Change Adaptation: Discourses, Policies and Practices

by Silja Klepp, Libertad Chavez-Rodriguez
9781138056299This edited volume brings together critical research on climate change adaptation discourses, policies, and practices from a multi-disciplinary perspective. Drawing on examples from countries including Colombia, Mexico, Canada, Germany, Russia, Tanzania, Indonesia, and the Pacific Islands, the chapters describe how adaptation measures are interpreted, transformed, and implemented at grassroots level and how these measures are changing or interfering with power relations, legal pluralismm and local (ecological) knowledge. As a whole, the book challenges established perspectives of climate change adaptation by taking into account issues of cultural diversity, environmental justicem and human rights, as well as feminist or intersectional approaches. This innovative approach allows for analyses of the new configurations of knowledge and power that are evolving in the name of climate change adaptation. Available On Amazon

From The Publisher:
Purchases on Amazon go to defray the cost of bringing you InnerSelf.comelf.com, MightyNatural.com, and ClimateImpactNews.com at no cost and without advertisers that track your browsing habits. Even if you click on a link but don't buy these selected products, anything else you buy in that same visit on Amazon pays us a small commission. There is no additional cost to you, so please contribute to the effort. You can also use this link to use to Amazon at any time so you can help support our efforts.

 

enafarzh-CNzh-TWnltlfrdehiiditjakomsfaptruesswsvthtrurvi

LATEST VIDEOS

Emergency Medicine For Our Climate Fever
by Kelly Wanser
As we recklessly warm the planet by pumping greenhouse gases into the atmosphere, some industrial emissions also…
What Extinction Rebellion climate activists are demanding from governments
by Democracy Now!
More than 700 climate activists were arrested in 60 cities worldwide in a global effort aimed at urging governments to…
Can Nature Repair The Planet From Climate Change?
by The Economist
A closer look at one of the most familiar responses offered to the climate crisis.
How Climate Change Is Threatening Homes In Mumbai
by South China Morning Post
Lowland cities and islands such as the Indian city of Mumbai may face increasingly frequent floods and storms
This is Not A Drill: 700+ Arrested as Extinction Rebellion Fights Climate Crisis With Direct Action
by Democracy Now!
More than 700 people have been arrested in civil disobedience actions as the group Extinction Rebellion kicked off two…
Europe's Most Iconic Mountain Is A Climate Change Warning
by ABC News
ABC News' James Longman reports from Mont Blanc, where a glacier on the Italian side of the mountain is breaking apart…
Something Drastic Has To Happen - Roger Hallam
by Extinction Rebellion
Roger Hallam talks with Stephen Sackur from BBC HardTalk about the need to ACT NOW.
Three Steps to Cut Your Carbon Footprint 60% Today
by TEDx Talks
Not all carbon is created equal. Writer Jackson Carpenter argues that the power to stop climate change rests on…

LATEST ARTICLES

Extreme Heatwaves Pose Spreading Threat
Extreme Heatwaves Pose Spreading Threat
by Tim Radford
Rising temperatures mean that heatwaves will become hotter, more frequent, last longer and will cover much wider areas.
Design For Flooding: How Cities Can Make Room For Water
Design For Flooding: How Cities Can Make Room For Water
by Elisa Palazzo
Science is clearly showing that the world is shifting towards a more unstable climate. Weather events like the flash…
How Unions Can Play A Leading Role In Tackling The Climate Crisis
How Unions Can Play A Leading Role In Tackling The Climate Crisis
by Matt Perry
How did a billionaire win over coal miners in Pennsylvania and West Virginia to become president? Three words: “Trump…
Rice Growing Produces Tonnes Of Excess Straw – Can We Turn It Into Bioenergy?
Rice Growing Produces Tonnes Of Excess Straw – Can We Turn It Into Bioenergy?
by Mirjam Roeder
For every tonne of rice produced, about a tonne of straw is grown. Given 770m tonnes of rice are produced each year,…
How Much Of Climate Change Is Natural? How Much Is Man-made?
How Much Of Climate Change Is Natural? How Much Is Man-made?
by Mark New
As someone who has been working on climate change detection and its causes for over 20 years I was both surprised and…
How The U.s. Power Grid Is Evolving To Handle Solar And Wind
How The U.s. Power Grid Is Evolving To Handle Solar And Wind
by Nate Berg
As renewable energy sources move mainstream, electricity generation and distribution systems are getting an extreme…
Emergency Medicine For Our Climate Fever
by Kelly Wanser
As we recklessly warm the planet by pumping greenhouse gases into the atmosphere, some industrial emissions also…
Mr. Delay, Mr. Deny And Canada's Precarious Climate Change Future
Mr. Delay, Mr. Deny And Canada's Precarious Climate Change Future
by Mark Winfield
During the recent federal leaders’ debate, Conservative Leader Andrew Scheer only distinguished himself on climate…