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.
Polyps of Schuchertinia allmanii. (Image Credit: Luis Martell, CC BY 4.0, Image cropped)
Earth is a fountain of incredible abundances and varieties of life-forms, with many of them still undiscovered. Biodiversity is a key pillar for our life as we know it, and we are not only a small fraction of it, but also use and harness this richness for the benefit of our own species’ advancement. Many human advances are based on other organisms’ attributes and talents, which is why we use certain species as “model organisms” when pioneering scientific breakthroughs. One example of such a specific form of life has helped us make some serious inroads into forms of regeneration and even immortality over the last few billion years ago, and leading us to great discoveries in science.
Image Credit: Oregon State University, CC BY-SA 2.0
Quantitative analysis of selected plastics in high-commercial-value Australian seafood by pyrolysis gas chromatography mass spectrometry (2020) Ribeiro et al., Environmental Science & Technology, https://doi.org/10.1021/acs.est.0c02337
Plastic is one of those things that we hear about all the time these days. More specifically, we hear about how there is an absolute ton of it in the environment thanks to human negligence and the lack of concern that a large amount of people have for where their plastic goes when they are finished with it. Plastic isn’t like paper or metal, it takes a long, LONG time for it to break down. Plastic bags take anywhere from 10-20 years, but the normal time it takes for most plastic waste to decompose is about 1000 years. To put that into perspective, Leif Erikson led an expedition from Greenland to the coast of what is now North America in the year 1002. If his crew had some plastic with them and left it in the places they visited (typical tourists) there’s a good chance that it would STILL be there today.
I hope I’ve convinced you why plastic is bad, but another danger that plastics pose are microplastics, small bits of plastic that have come from a larger piece, all of which are less than 5mm in size. Our environment is full of them, and the ocean in particular has been saturated with microplastics. In 2014 a research expedition sailed from Bermuda to Iceland (a trip of 2500 miles/4023 km) and found microplastics in every single sample they took. And that was just plastic in the environmental samples they took, the real threat to marine life comes from what happens to all of that microplastic.
Image Credit: Pentapfel, Pixabay licence, Image Cropped
Fascination with nature drives a huge chunk of tourism worldwide. The plains of Africa, the Amazon Rainforest, the Swiss Alps and their associated species are huge economic drivers for their respective countries, and they (ideally) increase people’s appreciation of nature. There are plenty of great examples of ecotourism as a pathway for both education and conservation.
Yet when an industry is driven by money first, nature second, of course there are going to be manifold examples of businesses deprioritising the natural phenomena they are associated with, often to the direct detriment of that phenomena. Think the masses of pollution now found around Mt Everest, or the damage caused by avid snorkellers on the Great Barrier Reef. I’ve had my own experience with tourist companies deliberately spreading misinformation about the reef – more on that at this link.
Image Credit: rumpleteaser, CC BY 2.0, Image Cropped
2019 was a year in which many changes that our planet is experiencing came to the fore, capped off in December by the Australian bushfires, a phenomenon that scientists predicted would start to occur with increasing intensity at the beginning of last decade. With all the change that our planet is currently undergoing, it’s always worth noting that the discipline of ecology itself has changed as well.
Over 2019 we got to sit down and talk to some pretty exciting people. And whether they were at the forefront of genomics, the science-policy interface, or the wave of inclusivity currently sweeping ecology, they all had some great comments on how ecology has changed over the last few decades.