Seaweed at a North-Atlantic coast.

Unraveling the enigma of the Atlantic's seaweed blobs

Seaweed in the Atlantic

These sprawling masses of seaweed, often stretching for miles, have been observed in the Atlantic over the past few years. While such occurrences are not entirely new, their increasing frequency and size have raised concerns about their potential environmental impacts.

A recent in-depth exploration by BBC Future sheds light on the phenomenon, unraveling the complex factors behind the enigmatic seaweed blooms.

How corals are surviving climate change

For more than two years, researchers on board the French expedition ship Tara sailed through the Pacific, stopping at almost 100 coral reefs to take thousands of water and coral samples. The expedition ended in 2018, and the analysis of the massive amount of data collected has taken five years.

Now, the initial results of the data analysis have been published. The findings should help us to better understand the living conditions of corals, to check their health status and to open up new possibilities for nature conservation. 

Ocean oxygen loss may ultimately reverse

Ocean deoxygenation has detrimental repercussions. Fish, crabs and other significant species of marine life that are unable to flee these low oxygen zones may perish as a result. People who depend on them for food and employment may be subsequently impacted by their absence as many of these species are economically significant.

Additionally, there is a negative feedback loop at play: as ocean oxygen levels decline, so does its capacity to absorb carbon dioxide. This may cause global warming to accelerate even further.

WMO declares onset of El Niño conditions

According to the WMO projections, there is a 90 percent chance that the El Niño event will persist over the second half of 2023. It is predicted to be at least moderately strong.

El Niño episodes typically last between nine and twelve months and occur every two to seven years on average. It is a naturally occurring climate pattern linked to the warming of the tropical Pacific Ocean's central and eastern ocean surface temperatures.

However, it occurs in a climate that has been altered by human activity.

Coiba National Park
A UNESCO World Heritage Site and marine reserve, Coiba National Park is found in the Gulf of Chiriqui in the western region of Panama. Immersed in the Tropical Eastern Pacific, it forms part of the Tropical Eastern Pacific Marine Corridor (CMAR).

$20 billion in marine biodiversity commitments announced at ocean conference

At the start of the event, US White House climate envoy and former secretary of state John Kerry said that the meeting was “so incredibly important because it is a conference that is focused on action, not on talk. It’s about real commitments and real solutions.”

Huge sums

Nearly $6 billion in US commitments spread across 77 projects to protect the high seas in 2023 was announced by Kerry, including technical cooperation to foster “green shipping corridors.”

Humpbacks in the South Pacific
Humpbacks in the South Pacific. Home to some of the largest reservoirs of biodiversity on the planet, which support abundant fisheries, marvelous deep-water coral ecosystems and diverse marine life, the high seas are also throughways for whales, sharks and other migratory species.

High Seas Treaty: Historic agreement to protect international waters reached at UN after 20 years of negotiations

The legal framework provides a crucial mechanism in setting up vast marine protected areas (MPAs) in the high seas. The historic treaty plays a critical role in the enforcement of the 30x30 pledge that countries had made in December 2022 at the United Nations Biodiversity Conference (COP15) in Montreal, Canada. The 30x30 target aims to protect a third of the sea (and land) by 2030.

The announcement by conference president, Rena Lee of Singapore, was met by a standing ovation from delegates, who had worked long days and nights to finalize the deal.

Motorboat in the Caribbean
Motorboat in the Caribbean (Flickr/CC BY-NC-ND 2.0)

Coral reef fish breed better with less motorboat noise

They then followed the breeding of spiny chromis and discovered that 65 percent of nests on quieter reefs still had offspring at the season’s end, compared to 40 percent on reefs with a lot of motorboat traffic. On quieter reefs, offspring were larger, and each nest had more offspring by the end of the season.

Some juvenile fish on coral reefs exposed to motorboat noise have stunted growth and may be half as likely to survive as fish on quieter reefs, owing to the noise pollution altering their parents' caregiving behavior, said the researchers.

Climate Change & the Growing Crisis of Our Oceans

Partically bleached coral in the Mediterranean Sea, Cape Carbonara, Sardinia. Photo by Lorenzo Moscia
Partially bleached colony of the madreporarian Cladocora caespitosa, one of the most important hard corals in the Mediterranean, at Cape Carbonara, Sardinia

Climate change is increasing the crisis of our seas, already under pressure due to several human activities. Rising temperatures are affecting and changing the underwater environment all over the world. The Mediterranean Sea, unfortunately, is no different from other seas. A group of specialists, coordinated by Greenpeace Italy, are monitoring the situation in the waters around Italy. Lorenzo Moscia reports.

Howard Johnson, Anilao Scuba Dive Centre, Shala Caliao, scuba diving news, PPE, COVID-19, face masks, plastic pollution, Rosemary E Lunn, Roz Lunn, X-Ray Mag, XRay Magazine, Philippines
Polymeric materials used in face masks can be a potential source of plastic and break down into microplastic pollution.

Abandoned face masks found on Philippine reef

The popular dive spot is southeast of the Philippine capital, Manila.

BBC Philippine correspondent Howard Johnson joined dive professionals from Anilao Scuba Dive Centre as they resumed diving, following the national lockdown. The dive centre is affiliated to the United Nations Environment Programme’s Green Fins, which promotes sustainable marine tourism in South-East Asia.

The 'Ghost Fishing' organisation puts divers centre stage

It was delivered by a very tall, quiet Dutchman by the name of Pascal van Erp. Pascal explained how he had started to recover abandoned ghost fishing gear entangled on wrecks in 2009. He soon inspired others to join him. It was not long before organised teams of volunteer technical divers were recovering tons of ghost fishing gear off the Dutch coastline. In 2012, Van Erp formally founded the not-for-profit Ghost Fishing organisation.