Washington: In the 21st century, mangrove forests around the world have experienced changes in ocean surface temperature, salinity, and density, according to recent research by Dr. Tom Van der Stocken of the VUB Biology Department. In the Indo-West Pacific, the main hotspot of mangrove diversity, the study revealed that changes in surface-ocean density may have an impact on the dispersal patterns of globally distributed mangrove species. The findings of the research were published in Nature Climate Change.
“Climate change affects sea-surface density via changes in temperature and salinity. Since propagules of widely distributed mangroves species have densities near that of seawater, changes in ocean density hold implications for oceanic dispersal of mangroves. Whether mangrove propagules float or sink depends on the difference between the densities of the propagules and that of the surrounding water.” says Tom Van der Stocken, Marie Sklodowska-Curie Postdoctoral Scholar at Vrije Universiteit Brussel, and research affiliate at the NASA Jet Propulsion Laboratory.
It is expected that warming winter temperatures and sea level rise will impact the distribution of these carbon-rich forests, but changes in surface-ocean properties might also influence distributional patterns through dispersal.
Mangroves are highly productive intertidal forests that occur along tropical, subtropical, and some temperate coasts. They support a broad variety of ecosystem goods and services and have an important place on the international climate mitigation and adaptation agenda. However, at the same time, these intertidal forests are strongly impacted by human activities and subjected to climate-driven changes in the marine, terrestrial and atmospheric processes to which they are tightly linked. While previous studies have focused on the potential impact of sea-level rise, altered precipitation regimes, and increasing temperature and storm frequency on mangrove ecosystems, the potential effects of climate-driven changes in seawater properties had not been considered.
Van der Stocken: “This is surprising, as the ocean is the primary dispersal medium of this ‘sea-faring’ coastal vegetation and dispersal is a key process that governs a species’ response to climate change by changing its geographical range.”
The paper, “Mangrove dispersal disrupted by projected changes in global seawater density”, is co-authored by VUB professors Bram Vanschoenwinkel and Nico Koedam, and in collaboration with the Moss Landing Marine Laboratories (MLML) and the University of California, Los Angeles (UCLA). The team made use of present and future sea-surface temperature and salinity data from the Bio-ORACLE database developed at Ghent University, and derived sea-surface density estimates from these data using the UNESCO EOS-80 equation of state polynomial for seawater.
Our study provides evidence that the density of surface-ocean waters along mangrove forests will decrease by the end of the 21st century, and a factor of two larger in the Indo-West Pacific region than in the Atlantic East Pacific, says Nico Koedam.
“It is important to note that our study uses present and future environmental conditions based on monthly averages and that the actual variability in sea-surface density around these mean values could be higher than that predicted in this study,” adds Vanschoenwinkel.
Van der Stocken: “There is still uncertainty on exactly how the projected changes in seawater density will impact realized mangrove dispersal in different parts of the world and more research is needed regarding the biological response of mangroves to climate-driven changes in surface-water properties. In this study, we took advantage of marine data layers to fill this gap, and we hope that our study will help to inspire new research that will quantify the effects of changes in the properties of the ocean surface on propagule floating periods, dispersal, and connectivity.”
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
NDTV – Dettol have been working towards a clean and healthy India since 2014 via the Banega Swachh India initiative, which is helmed by Campaign Ambassador Amitabh Bachchan. The campaign aims to highlight the inter-dependency of humans and the environment, and of humans on one another with the focus on One Health, One Planet, One Future – Leaving No One Behind. It stresses on the need to take care of, and consider, everyone’s health in India – especially vulnerable communities – the LGBTQ population, indigenous people, India’s different tribes, ethnic and linguistic minorities, people with disabilities, migrants, geographically remote populations, gender and sexual minorities. In wake of the current COVID-19 pandemic, the need for WASH (Water, Sanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign will continue to raise awareness on the same along with focussing on the importance of nutrition and healthcare for women and children, fight malnutrition, mental wellbeing, self care, science and health, adolescent health & gender awareness. Along with the health of people, the campaign has realised the need to also take care of the health of the eco-system. Our environment is fragile due to human activity, which is not only over-exploiting available resources, but also generating immense pollution as a result of using and extracting those resources. The imbalance has also led to immense biodiversity loss that has caused one of the biggest threats to human survival – climate change. It has now been described as a “code red for humanity.” The campaign will continue to cover issues like air pollution, waste management, plastic ban, manual scavenging and sanitation workers and menstrual hygiene. Banega Swasth India will also be taking forward the dream of Swasth Bharat, the campaign feels that only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and the country can become a Swasth or healthy India.