Sea Level Rise Threatens Sea Turtles: New Research Findings

Sea level rise (SLR) is a looming threat to ecosystems worldwide, particularly coastal habitats and the species that rely on them. Among those vulnerable creatures are sea turtles. As the repercussions of climate change remain, understanding the potential consequences for sea turtles becomes increasingly crucial.

A recent paper elaborates on this topic, exploring the vulnerability of sea turtle nesting sites to SLR (Rivas et al., 2023)¹. Published in a Scientific Journal, the study employs a new, cost-effective methodology to assess the future of these species under various climate scenarios. Let’s see the findings and their implications.

Jump Links

Current Context of Sea Level Rise
A New Approach to Assessing Sea Level Rise-Induced Vulnerability
Research Findings: A Concerning Future for Sea Turtles
Sea Level Rise Shows Different Effects Among Sea Turtle Species
Looking Ahead: Conservation Imperatives
Conclusion: Sea level rise is a looming threat for humans and animals alike.

You might be wondering why you should care about the impact of sea level rise on sea turtle populations. The truth is, as we elaborate further on the post, that humans rely on thriving biodiversity to survive. All of the resources humans use to produce food, shelter, and economies come from nature. Animals, such as sea turtles, serve a role in their respective ecosystem with their demise causing a ripple effect that reaches humans and other animals, which continues on a never-ending cycle of loss.

Reading about the impact of sea level rise on sea turtles is also getting to know the impact of sea level rise on the future of the generations to come. Or even your future if you are younger than 75 years old, as some of the consequences we see here are projected to materialize as soon as 25 years from now.

If you want to know more about some currently endangered species whose survival is also imperative for a sustainable future, read here:

Now, onto the blog post. Save the pin below to always have it on hand, in case you’d like to read it later!

Current Context of Sea Level Rise

Before going into the specifics of the study, it’s essential to grasp the context surrounding sea level rise (SLR). Recent data paints a stark picture: global sea levels are rising at an unprecedented rate, outstripping anything observed over the past two millennia. As of December 2023, the latest measurement indicates a global mean sea level rise of 104 (± 4.0) mm, highlighting the urgency of understanding and addressing this pressing issue.

_{Graph by NASA.}

Causes of sea level rise

What’s driving this alarming trend? The primary culprits are directly linked to human-caused global warming. Firstly, the added water from melting ice sheets and glaciers contributes significantly to rising sea levels. Secondly, the expansion of seawater as it warms exacerbates the problem further. These factors, compounded by climate change, have accelerated sea level rise in recent decades.

Projections paint a dire picture for the future. By the end of this century, sea levels could reach alarming levels, posing significant threats to coastal habitats globally. The implications for communities, economies, animals, and ecosystems are profound and necessitate urgent action.

Tracking the current state of sea level rise

Observing and monitoring sea level rise is essential for understanding its dynamics and informing mitigation strategies. Over the past 27 years, satellite altimeters have been instrumental in tracking global mean sea level changes. The data gathered from these satellites reveal a consistent rise in sea levels, with an average annual increase of 3.4 millimeters per year since 1993.

In addition to satellite altimeters, other observation systems such as GRACE and GRACE-FO satellites, as well as Argo profiling floats, provide valuable insights into the individual processes contributing to sea level rise. These systems help us understand the complex interplay between ice melt, thermal expansion, and landwater storage, ultimately contributing to a more comprehensive understanding of the factors driving sea level rise.

Consequences of sea level rise

The accelerating rise of sea levels represents one of the most pressing challenges of our time. As we strive to address the looming threat of sea level rise, it is essential to consider the interconnectedness of ecosystems and species. With sea levels rising at an unprecedented rate, the threat to coastal habitats and the species that rely on them, such as sea turtles, becomes increasingly evident.

Some of the consequences of sea level rise on animals such as sea turtles include:

Loss of Nesting Habitat: Rising sea levels contribute to increased erosion of coastal habitats. Eroded habitats can destabilize nesting sites. This makes coastal animals such as sea turtles, seabirds, marine iguanas, and seals struggle to find suitable areas to breed and rear their young, leading to declines in population.
Loss of Foraging Grounds: Coastal habitats, such as seagrass beds, mangrove forests, and intertidal zones, are important foraging grounds for a variety of coastal animals, including fish, crustaceans, and shorebirds. Sea level rise can result in the deterioration of these habitats, and even total loss.
Increased Vulnerability to Predators: Sea level rise can alter coastal ecosystems and change predator-prey dynamics. As coastal habitats erode and diminish, animals may become more vulnerable to predation by terrestrial and marine predators.
Shifts in Distribution: Rising sea levels can force coastal animals to relocate to higher ground or seek alternative habitats. This may result in shifts in the distribution of coastal animal populations, leading to changes in their abundance, diversity, and interactions with other species within their ecosystems.
Cascade Effects on Ecosystems: The consequences of sea level rise for coastal animals can have ripple effects throughout their ecosystems. Changes in their populations can impact ecosystem dynamics, including nutrient cycling, habitat structure, and the abundance of other species.

A New Approach to Assessing Sea Level Rise-Induced Vulnerability

The study “Uncertain future for global sea turtle populations in face of sea level rise” pioneers a low-cost approach to assess the impacts of sea level rise (SLR) on sea turtles. By combining freely available digital elevation models with projections of SLR, researchers evaluate the vulnerability of sea turtle nesting sites across seven rookeries worldwide. These rookeries encompass nesting habitats for five species of sea turtles, ranging from vulnerable to critically endangered.

“A Rookery of Turtles refers to a gathering or colony of turtles. This collective noun phrase comes from the term rookery, which usually describes a breeding ground or nesting area for birds. However, it is adapted here to represent the congregation of turtles in a specific location or habitat.”
– “A Rookery of Turtles“ Collective Nouns List

The heart of the study lies in its comprehensive examination of sea turtle nesting habitats and their susceptibility to the encroaching threat of sea level rise (SLR). With a wealth of data, researchers analyzed the GPS locations of 2835 marine turtle nests belonging to five different species across seven distinct study areas worldwide. Their goal? To gauge the vulnerability of these nests to flooding amidst the backdrop of projected SLR caused by climate change spanning from 2010 to 2100.

Armed with GPS nest locations, available Digital Elevation Models (DEMs), and Intergovernmental Panel on Climate Change (IPCC) projections, the team scrutinized the mean estimated elevation for nest sites across different DEM sources for each rookery.

Research Findings: A Concerning Future for Sea Turtles

_{Water reaching a Leatherback turtle nesting site in the Caribbean. Photo by Jolo Diaz via Pexels}

The results paint a sobering picture. By 2050, under moderate climate change scenarios, some sea turtle nesting habitats could face complete inundation.

Raine Island in Australia and Saona Island in the Dominican Republic emerge as the most vulnerable populations. By 2050, 100% nest flooding is projected for these rookeries under moderate emissions scenarios.
Conversely, Cuba exhibits a lower vulnerability to flooding throughout the twenty-first century, possibly attributed to its elevated beaches.
Rookeries in Costa Rica, and the USA are particularly at risk, with the potential for massive flooding threatening the future of these populations. For Florida, flooding probability will increase immensely after 2050.
Under a scenario outlined by the Intergovernmental Panel on Climate Change (IPCC) that assumes a moderate level of greenhouse gas emissions, flat islands and cays, particularly those in the Caribbean and Pacific regions, are at heightened risk from rising sea levels. These areas are vital nesting grounds for sea turtles, known for their habit of returning to their birthplace every few years to lay eggs. Additionally, these places accommodate various turtle species and offer diverse nesting conditions.

However, nuanced differences in flooding vulnerability emerge among species within rookeries, showcasing the intricacies of sea turtle nesting dynamics.

Sea Level Rise Shows Different Effects Among Sea Turtle Species

The study also highlights disparities in vulnerability among sea turtle species.

_{A Leatherback turtle nesting site. Photo by Jolo Diaz via Pexels}

Leatherback turtles, known for nesting in open areas near the high tide line, are identified as particularly at risk.

In contrast, species like the hawksbill and green turtles, which nest at higher elevations closer to dunes, may face lower immediate risks.

_{Hawksbill sea turtle swimming. Photo by Belle Co via Pexels}

Looking Ahead: Conservation Imperatives

With these new insights, conservationists face a pressing challenge. Urgent action is needed to protect sea turtle populations from the consequences of climate change.

Management strategies, including sand refilling of nesting beaches and relocation of nests to safer areas, may provide short-term relief. However, the ultimate solution lies in curbing anthropogenic emissions to mitigate sea level rise.

Why is important to save sea turtles from the consequences of sea level rise

Sea turtles play a vital role in maintaining the health of marine ecosystems, making their conservation critical for both environmental and human well-being.

_{Hawksbill sea turtle in its habitat. Photo by keemkai villadums via Pexels.}

Here’s why saving these creatures is of utmost importance:

Biodiversity Preservation: Sea turtles are integral components of marine biodiversity, contributing to the balance and resilience of ocean ecosystems. As predators, they help regulate populations of jellyfish, seagrasses, and other marine species. Thereby maintaining the health and stability of marine food webs.
Economic Value: Sea turtles are valuable assets for coastal economies, supporting tourism through activities such as turtle watching and eco-tourism. The presence of thriving sea turtle populations can attract visitors, stimulate local businesses, and generate revenue for coastal communities.
Cultural Significance: For many coastal communities around the world, sea turtles hold deep cultural and spiritual significance. They are revered symbols of wisdom, longevity, and resilience. With their conservation often intertwined with cultural traditions and practices passed down through generations.
Indicator of Ecosystem Health: The status of sea turtle populations serves as an important indicator of the overall health of marine environments. Declines in sea turtle populations can signal underlying issues such as habitat degradation, pollution, and overfishing. Alerting us about broader ecological concerns that require attention.
Education: Healthy sea turtle populations attract researchers, providing opportunities for educational outreach and scientific study.

Conclusion: Sea level rise is a looming threat for humans and animals alike.

In this blog, we try to bring to light the interconnectedness of biodiversity. The consequences of sea level rise on coastal animals, such as sea turtles, affect humans. This is because humans depend on thriving ecosystems to survive, as they control the weather as well as the availability of food and resources the economy relies upon. Losing one species or seeing changes in their feeding and reproducing patterns, will destabilize these ecosystems humans depend on.

In essence, safeguarding sea turtles is not just about protecting a single species. It’s about preserving the intricate systems that sustain our oceans and, by extension, our planet. By taking steps to conserve sea turtles and their habitats, we can contribute to the broader goal of ensuring a sustainable future for generations to come.

The study we reviewed in this post serves as evidence of the need for global cooperation and concerted efforts to combat climate change. The paper represents a critical step forward in understanding the impacts of Sea level rise. By leveraging innovative methodologies, researchers provide invaluable insights into the vulnerabilities caused by it.

Notes

Rivas, M. L., Rodríguez-Caballero, E., Esteban, N., et al. (2023). Uncertain future for global sea turtle populations in face of sea level rise. Scientific Reports, 13(1), 5277. https://doi.org/10.1038/s41598-023-31467-1 ↩︎