Image Credit: Sharkcrew, CC BY-SA 4.0, Image Cropped
In February 2022, a British swimmer was killed by a great white shark (Carcharadon carcharias) near Sydney, Australia. Unsurprisingly, this gained significant media attention. State authorities launched a search for the culprit, with the aim of culling/relocating it away from people. This plan would seem, on the surface, to make perfect sense – shark ate human, make it go away. Yet this logic is largely based on a widespread misconception, and an outdated theory that science has long since abandoned.
Fun Fact #1: Elephant seal blood has a high haemoglobin content (to help them make long, oxygen deprived, dives) which makes their blood BRIGHT red.
Fun Fact #2: This results in some pretty striking colours when blood is spilled. We tried to replicate it in the comic, but nothing matches the original (see below).
Tanya Strydom is a PhD student at the Université de Montréal, mostly focusing on how we can use machine learning and artificial intelligence in ecology. Current research interests include (but are not limited to) predicting ecological networks, the role species traits and scale in ecological networks, general computer (and maths) geekiness, and a (seemingly) ever growing list of side projects. Tweets (sometimes related to actual science) can be found @TanyaS_08.
A hydrozoan jellyfish (Crossoto sp.) observed during the NOAA Deepwater Exploration of the Marianas expedition in 2016 and filmed at a depth of around 3700m. (Image Credit: NOAA Ocean Exploration & Research, CC BY-SA 2.0, Image cropped)
With the publication of the new IPCC climate report, I am once again asking myself: What can I do to mitigate the problems that our world is facing? Climate breakdown, pollution, loss of wildlife… our planet suffers from humans’ greed, selfishness and destructive exploitation. It seems almost impossible for one to have any influence or power for change. Global and political action is the only way to tackle the drastic and life-defining challenges that we and future generations will be confronted with.
Image Credit: Paresh Poriya, CC BY 4.0, Image Cropped (also not featuring tunicates)
Testing ecological theories in the Anthropocene: alteration of succession by an invasive marine species (2021) Christianson et al., Ecosphere, https://doi.org/10.1002/ecs2.3471
Ecological disturbances, such as fire, floods, or storms, might seem like a catastrophe at first glance, but often they open up space for new species to take the place of dominant ones, creating a more diverse ecosystem. When a disturbance occurs matters as well – if a storm hits right before a particular species starts to reproduce, that species could take advantage of the extra space and become dominant in a short time.
In the 1970s, John Sutherland and Ronald Karlson tested this theory, looking at the invertebrate community of a coastal dock in North Carolina, USA. They found that which species dominated depended on when the community began to grow (a proxy for when disturbance opened up new space).
The area has since seen the introduction of an invasive species of tunicate, Clavelina oblonga. This week’s authors wanted to test whether the original patterns seen in the 1970s still showed up in the presence of the invader.
A flatworm (Pseudocerus liparus) crawling on a sponge – passing through a forest of hydroids and tunicates. (Image credit: Christa Rohrbach, CC BY-NC-SA 4.0)
Last week I posted an article about fascinating creatures that escape death almost completely, including the famous “immortal jellyfish” (link below). Yet while the jellyfish’s attitude to aging is awe-inspiring, its existence poses a more obvious, yet perplexing question: why do we age?
The hydromedusa of Podocoryna borealis. (Image credit: Lara Beckmann, NorHydro, CC BY-SA 4.0)
Our existences are often centered around the hope that we will live a long and fulfilled life. At the same time, while we aim to grow old, many of us abhor the aging process, dreaming of remaining young and healthy for as long as possible. It explains why we are so fascinated by the concept of immortality. Think of vampire stories, constant quests for the fountain of youth, or even the newest anti-aging products in the drugstore next door. But apart from the few extra years we gain nowadays through modern medicine and improved life circumstances, many of us can’t extend our lives much further.
We share this fate with many other animals that go through the stages of birth, growth, reproduction and death. But despite that, we don’t need to rely on science-fiction to get a glimpse of everlasting life: some organisms on our planet don’t follow these stages and some cheat it altogether – escaping death almost completely.
A young octopus (Graneledone verrucosa) moves across the seafloor. Observed during the Okeanos Explorer Northeast U.S. Canyons 2013 expedition. (Image Credit: NOAA Ocean Exploration & Research, CC BY-SA 2.0, Image cropped)
In nature every death brings new life. A fascinating example are whale-falls: when a whale dies, its carcass will sink down to the ocean floor where it creates a unique ecosystem for bottom-dwelling organisms. Whales’ bodies can weigh up to 200 tons and contain massive amounts of fat and proteins. When a dead whale reaches the ocean floor it brings a lot of resources to an environment which is usually limited by food availability. The fortunate creatures experiencing the whale-fall welcome such a great source of nutrition, and use up everything they can, until the last vertebra is decomposed.
Image Credit: Andrei Savitsky (left and right), CC BY-SA 4.0 ; Uwe Kils (centre), CC BY-SA 3.0
The deep sea is a wondrous world of biodiversity, darkness, and mysteries we still know very little about. Despite the fact that we rely on the deep sea as a sink for carbon dioxide – and increasingly as a source of natural gases and minerals – we have very little understanding of how our actions will affect its intricate food web.
Near the base of the food web sits an incredibly diverse group of animals called copepods. They are so abundant and have such sweeping variety that we are still struggling to come up with a way to classify them. Dr. Nancy Mercado-Salas has worked with these tiny creatures since her bachelor’s thesis, both in freshwater and in marine ecosystems, and her message is clear: We need to increase our knowledge on this group of animals before it is too late.