In this post, Prof. Gil Rilov—Senior Scientist at the National Institute of Oceanography, Israeli Limnological and Oceanographic Research (IOLR), as well as Associate Professor, at the University of Haifa, Israel—discusses his recently published review paper ‘Ecological impacts of invasive ecosystem engineers: A global perspective across terrestrial and aquatic systems’. Gil discusses the impacts, positive and negative, of alien invasions, his love of diving, and what ecology is all about.
About the paper
Think of your garden hedge or the trees in the nearby park, creating shade, breaking the wind and digging into the earth with their roots. Think of beavers shifting river flows with their dams, or hundreds of earthworms reworking the soil after the rain, nourishing it with rich organic matter. These organisms are considered by ecologists to be “ecosystem engineers”, because they considerably change or “engineer” the environment for other species with their body or actions. For centuries, thousands of such species have been moved around the world by humans—intentionally or unintentionally—and introduced to new regions. These newcomers, aliens in their new environment, can dramatically shift the terrestrial, freshwater, or marine ecosystems they invade, as well as their functions. Some of them can also have dramatic economic impacts on human societies. When alien species have considerable negative ecological and or economic impacts they are considered invasive. One very well-known example is the “zebra mussel” that invaded the Great Lakes in the USA from Europe, transforming local biodiversity, filtering out most of the plankton from the water, and also strongly impacting local infrastructures and economies.
Almost 30 years after the term “ecosystem engineers” was coined by Jones and his colleagues in 1994—and with the increase in the rate and impact of invasive species including engineers—our review paper provides the first global view on the state of knowledge regarding the ecological impacts of invasive ecosystem engineers in all realms. My co-authors and I also present perspectives on the potential impact of invasive ecosystem engineers on ecosystem services, especially during the age of climate crisis, when many thermally-sensitive native species are beginning to disappear in climate change hotspots and thermophilic alien engineers that establish there could either compensate for the natives’ loss if they have similar traits and ecological function functions or be different and could disrupt the invaded ecosystem and its functions and possibly services.
About the research
The literature that has accumulated on the impacts of invasive ecosystem engineers in the past two decades is impressive. To summarize it and comprehensibly analyze it—in order to search for trends across all realms—is a huge task that will probably be the endeavor of future efforts.
In our review, we aim to take a broad perspective on the topic, providing compelling examples from all realms of major invasive engineers and examining the context dependency of their impacts. In addition to this, we also suggest future directions of research which are needed under rapid global change. The impacts of invasive ecosystem engineers are often negative; however, they sometimes can be positive and impacts can depend strongly on the traits of the invaded ecosystem or even the time of year. Even the American beaver has become invasive—following its introduction to Tierra del Fuego for its fur—and has quickly transformed forests and rivers, strongly affecting the local biota and ecosystem functioning. The American beaver has also increased the growth of another invader—the brown trout.
In the marine realm, invasive crabs destroy shorelines by burrowing into banks, while invasive macroalgae, seagrasses, and bivalves can dramatically affect local diversity and carbon cycling. Importantly, in a fast-warming globe, where thermally-sensitive native species disappear, thriving alien engineers with similar traits may preserve or restore important ecosystem functions and services. A perfect place to test these questions is my own ‘backyard’—the coast of the Levantine Basin in the southeast Mediterranean Sea, a hotspot of ocean warming and bioinvasions arriving mainly via the nearby Suez Canal.
About the author
To me, ecology is a quest to identify the building blocks and workings that make the living world, well, work. As ecologists, we try to decipher the secrets of biodiversity and investigate how humans disrupt it. Many of us also seek nature-based solutions to the problems caused by humanity. This is a very complex task because, obviously, nature is highly complex, but it’s a worthwhile effort. As a kid, I climbed trees, played with ants, observed tadpoles turning into frogs in a large flowerpot, and dreamed of expeditions to the jungles of the Amazon or observing gorillas in the foggy mountains of Congo. As a young adult, I also dived on the amazing reefs of the Red Sea. Today, I am a marine community ecologist and I have been studying coastal oceans around the world for the past few decades, from the coral reefs in the Red Sea, through to the rocky shores of New Zealand and Brazil, to invasive seagrass in the Caribbean.
My lab at IOLR is set on the coast of Haifa, Israel, and focuses on studying the impacts of climate change, bioinvasions, and local stressors on species, communities, ecosystems, and their functioning. I perform most of my studies in the Mediterranean Sea, but, together with colleagues, also in many other regions around the globe. One main focus of my team and students is to assess and compare the habitat provisioning and metabolic functioning of relatively intact versus altered (including invaded) macrophyte communities on shallow rocky reefs. We also use state-of-the-art mesocosm facilities to simulate future ocean conditions in order to forecast how native/alien species and communities will survive and function under different climate change scenarios.
I love being an ecologist! I get to explore beautiful coastlines around the world, dive in amazing places, and feel that I contribute to the understanding of nature, and, maybe, how to better protect it from us. To me, this is not really work but pleasure… well… most of the time. Don’t get me wrong, doing science is very hard work at times, with many frustrations along the way, and it never leaves you, mentally. Furthermore, as a lab head, you actually spend most of the time in front of the computer, writing grant proposals, reports or papers. However, ultimately, it’s worth it.
In my spare time I enjoy yoga, cycling, and try to improve my ceramic and pottery skills. Sometimes, weird marine creatures come out of my hands and into the kiln, once even a yellow octopus!
Enjoyed the blogpost? Read the research here!
