̽��ֱ�� of Cambridge - marine conservation

̽��ֱ��coral whisperer

lkm37 — Tue, 25 Feb 2025 09:41:11 +0000

Duygu Sevilgen has built a coral lab in the basement of an old Zoology building. Here, 10 experimental tanks host multicoloured miniature forests, with each tank representing a different marine environment. Duygu uses extremely small sensors to record the fine details of coral skeletons and listen to their dialogue with algae. In doing so, she determines how much change corals can bear, and improves our chances of saving them in the wild.

Solent Seascape

lkm37 — Wed, 09 Oct 2024 10:04:29 +0000

Inside the momentous effort to restore a precious marine world.

World’s most threatened seabirds visit remote plastic pollution hotspots

jg533 — Tue, 04 Jul 2023 15:00:00 +0000

̽��ֱ��extensive study assessed the movements of 7,137 individual birds from 77 species of petrel, a group of wide-ranging migratory seabirds including the Northern Fulmar and European Storm-petrel, and the Critically Endangered Newell’s Shearwater.

This is the first time that tracking data for so many seabird species has been combined and overlaid onto global maps of plastic distribution in the oceans.

̽��ֱ��results show that plastic pollution threatens marine life on a scale that transcends national boundaries: a quarter of all plastic exposure risk occurs in the high seas. This is largely linked to gyres - large systems of rotating ocean currents - where vast accumulations of plastics form, fed by waste entering the sea from boats, and from many different countries.

Seabirds often mistake small plastic fragments for food, or ingest plastic that has already been eaten by their prey. This can lead to injury, poisoning and starvation, and petrels are particularly vulnerable because they can’t easily regurgitate the plastic. In the breeding season they often inadvertently feed plastic to their chicks.

Plastics can also contain toxic chemicals that can be harmful to seabirds.

Petrels are an understudied but vulnerable group of marine species, which play a key role in oceanic food webs. ̽��ֱ��breadth of their distribution across the whole ocean makes them important ‘sentinel species’ when assessing the risks of plastic pollution in the marine environment.

“Ocean currents cause big swirling collections of plastic rubbish to accumulate far from land, way out of sight and beyond the jurisdiction of any one country. We found that many species of petrel spend considerable amounts of time feeding around these mid-ocean gyres, which puts them at high risk of ingesting plastic debris,” said Lizzie Pearmain, a PhD student at the ̽��ֱ�� of Cambridge’s Department of Zoology and the British Antarctic Survey, and joint corresponding author of the study.

She added: “When petrels eat plastic, it can get stuck in their stomachs and be fed to their chicks. This leaves less space for food, and can cause internal injuries or release toxins.”

Petrels and other species are already threatened with extinction due to climate change, bycatch, competition with fisheries, and invasive species such as mice and rats on their breeding colonies. ̽��ֱ��researchers say exposure to plastics may reduce the birds’ resilience to these other threats.

̽��ֱ��north-east Pacific, South Atlantic, and the south-west Indian oceans have mid-ocean gyres full of plastic waste, where many species of threatened seabird forage.

“Even species with low exposure risk have been found to eat plastic. This shows that plastic levels in the ocean are a problem for seabirds worldwide, even outside of these high exposure areas,” said Dr Bethany Clark, Seabird Science Officer at BirdLife International and joint corresponding author of the study.

She added: “Many petrel species risk exposure to plastic in the waters of several countries and the high seas during their migrations. Due to ocean currents, this plastic debris often ends up far away from its original source. This highlights the need for international cooperation to tackle plastic pollution in the world’s oceans.”

̽��ֱ��study also found that the Mediterranean Sea and the Black Sea together account for over half of petrels’ global plastic exposure risk. However, only four species of petrel forage in these enclosed, busy areas.

̽��ֱ��study was led by a partnership between the ̽��ֱ�� of Cambridge, BirdLife International and the British Antarctic Survey, in collaboration with Fauna & Flora International, the 5 Gyres Institute, and over 200 seabird researchers in 27 countries.

It was published on 4 July in the journal Nature Communications.

To get their results, the researchers overlaid global location data, taken from tracking devices attached to the birds, onto pre-existing maps of marine plastic distribution. This allowed them to identify the areas on the birds’ migration and foraging journeys where they are most likely to encounter plastics.

Species were given an ‘exposure risk score’ to indicate their risk of encountering plastic during their time at sea. A number of already threatened species scored highly, including the Critically Endangered Balearic Shearwater, which breeds in the Mediterranean, and Newell’s Shearwater, endemic to Hawaii.

Another Endangered species, the Hawaiian Petrel also scored high for plastic exposure risk, as did three species classified by the IUCN as Vulnerable: the Yelkouan Shearwater, which breeds in the Mediterranean; Cook’s Petrel, which breeds in New Zealand, and the Spectacled Petrel, which only breeds on an extinct volcano called Inaccessible Island, part of the Tristan da Cunha archipelago, a UK Overseas Territory.

“While the population-level effects of plastic exposure are not yet known for most species, many petrels and other marine species are already in a precarious situation. Continued exposure to potentially dangerous plastics adds to the pressures,” said Professor Andrea Manica at the ̽��ֱ�� of Cambridge’s Department of Zoology, a co-author of the study.

He added: “This study is a big leap forward in understanding the situation, and our results will feed into conservation work to try and address the threats to birds at sea.”

̽��ֱ��research was funded by the Cambridge Conservation Initiative’s Collaborative Fund for Conservation, sponsored by the Prince Albert II of Monaco Foundation, and the Natural Environment Research Council.

Reference

Clark, B.L. et al.: ‘Global assessment of marine plastic exposure risk for oceanic birds.’ Nature Communications, July 2023. DOI: 10.1038/s41467-023-38900-z

Analysis of global tracking data for 77 species of petrel has revealed that a quarter of all plastics potentially encountered in their search for food are in remote international waters – requiring international collaboration to address.

Ocean currents cause big swirling collections of plastic rubbish to accumulate far from land

Lizzie Pearmain

Beth Clark

Northern Fulmar bird in flight

̽��ֱ��text in this work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

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‘Antisocial’ damselfish are scaring off cleaner fish customers – and this could contribute to coral reef breakdown

cg605 — Thu, 23 Feb 2023 09:00:35 +0000

̽��ֱ��meal of choice for the Caribbean cleaner fish, the sharknose goby, is a platter of parasites, dead tissue, scales and mucus picked off the bodies of other fishes. By removing these morsels, gobies are offering their ‘cleaning services’ to other marine life – a famous example of a mutually beneficial relationship between species.

But new research from the ̽��ֱ�� of Cambridge and Cardiff ̽��ֱ�� shows that when gobies inadvertently set up shop within the territories of aggressive damselfish, damselfish scare off the gobies’ ‘choosy client customers’.

̽��ֱ��study, published today in Behavioral Ecology, is an example of a largely unexplored phenomenon: a mutually beneficial relationship in nature being disrupted by a third party.

Sharknose gobies work solo or band together and set up a ‘cleaning station’: a fixed location in a particular nook of coral reef, where other marine life burdened by parasites go to take advantage of the gobies’ dietary needs.

“Gobies wait at cleaning stations for customers to visit, similar to shops. And with customers, come the parasites,” said Dr Katie Dunkley, a behavioural ecologist at the ̽��ֱ�� of Cambridge’s Department of Zoology. “In return for providing a cleaning service the gobies receive a payment of food.”

Customers are varied and include parrotfish, surgeonfish and butterflyfish. These choosy client fish shop around, visiting different cleaning stations open for business. If interested, they will adopt a stationary pose that makes a clean more likely – typically a head or tail-stand position with all fins flared.

During a clean – which could last from a few seconds to several minutes – gobies make physical contact with the customer, removing parasites and other dead body tissue. This is known as ‘tactile stimulation’ and, as well as getting rid of parasites, it may act as a massage reducing the customer’s stress, says Dunkley. Previous research has established the importance of cleaners – their removal led to fewer numbers and less variety of fish species on reefs.

“Cleaning stations act as a marketplace, and if customers stop showing up, over time a cleaning station is going to go out of business,” said Dunkley.

Five researchers spent over 34 hours observing cleaning stations on a shallow fringing reef in Tobago over a period of six weeks. Equipped with snorkels and waterproof paper they recorded underwater interactions for 10-minute periods from 8am-5:15pm each day.

They found that client fish were less likely to go to cleaning stations that were more often patrolled by damselfish, who scared ‘intruders’ away.

“I thought that damselfish might play a role as they visit cleaning stations too – although don’t often get cleaned – but to see just how influential they were was startling.

“Damselfish act like farmers as they weed out algae they don’t want, to encourage their preferred algae to grow. Damselfish are protective over their algal territories, and these antisocial fish spend a lot of time patrolling their territories, scaring away intruders through biting, attacking, chasing or threatening displays.”

Damselfish’s territories cover up to 70% of some reefs. On a healthy coral reef, a balance is maintained between algae and coral. But as reefs deteriorate and overfishing intensifies, algae thrive. As reefs deteriorate damselfish may become more common and/or aggressive – leading to fewer species receiving the goby cleaning treatment needed to keep them healthy, says Dunkley. This could ultimately contribute to the breakdown of delicate ecosystems supported by reefs.

“In future we’d like to tease out the motives of damselfish. Are they driven by wanting to protect their algae farms or monopolise cleaning stations?” said Dunkley, a Charles Darwin and Galapagos Islands Fund Junior Research Fellow at Christ’s College, Cambridge.

“Just as humans are connected through family, friends and colleagues, all fish are connected to each other. It’s important that we don’t just look at relationships in isolated bubbles. We need to step back and see how all fish are connected so that we can protect ecosystems like coral reefs.”

̽��ֱ��study was funded by a Natural Environment Research Council GW4+ studentship and Christ’s College ̽��ֱ�� of Cambridge Galapagos Islands Fund (both awarded to first author, Katie Dunkley). Last author, James Herbert-Read, was supported by the Whitten Lectureship in Marine Biology, and a Swedish Research Council Grant (2018–04076).

Dunkley et al, ̽��ֱ��presence of territorial damselfish predicts choosy client species richness at cleaning stations, Behavioral Ecology, DOI: doi.org/10.1093/beheco/arac122

Damselfish have been discovered to disrupt ‘cleaning services’ vital to the health of reefs. And climate change may mean this is only likely to get worse.

"We need to step back and see how all fish are connected so that we can protect ecosystems like coral reefs."

Dr Katie Dunkley

Secrets of the reef revealed

Federica Grassi / Moment via Getty Images

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes