Björn Illing

Thünen Institute | vTI · Institute of Fisheries Ecology

Metamorphosis is a critical aspect of coral reef fish ecology. This developmental milestone marks changes in form and function that permit successful transition of pelagic larvae to the demersal lifestyle on coral reefs. However, we know very little about the physiological changes that occur during this period, specifically potential changes in ene...

The anadromous European smelt (Osmerus eperlanus) plays a key role in food webs of many riverine ecosystems in Europe. However, population sizes in several German rivers (e.g. Elbe or Weser rivers) have diminished drastically over the past decade. Turbidity has been considered one of the stressors affecting the successful recruitment of European sm...

Mass coral bleaching events coupled with local stressors have caused regional-scale loss of corals on reefs globally. Following the loss of corals, the structural complexity of these habitats is often reduced. By providing shelter, obscuring visual information, or physically impeding predators, habitat complexity can influence predation risk and th...

Connectivity of coral reef fish populations relies on successful dispersal of a pelagic larval phase. Pelagic larvae must exhibit high swimming abilities to overcome ocean and reef currents, but once settling onto the reef, larvae transition to endure habitats that become hypoxic at night. Therefore, coral reef fish larvae must rapidly and dramatic...

Anadromous European smelt (Osmerus eperlanus) is a keystone species in lake and river ecosystems. In the past and present, stock declines in several of its habitats have been reported. The reasons for this are unclear. Experimental research on the early life stages could help to reveal the potential causes. For this purpose, knowledge on artificial...

Understanding the drivers behind fluctuations in fish populations remains a key objective in fishery science. Our predictive capacity to explain these fluctuations is still relatively low, due to the amalgam of interacting bottom-up and top-down factors, which vary across time and space among and within populations. Gaining a mechanistic understand...

Coral reef fishes and the ecosystems they support represent some of the most biodiverse and productive ecosystems on the planet yet are under threat as they face dramatic increases in multiple, interacting stressors that are largely intensified by anthropogenic influences, such as climate change. Coral reef fishes have been the topic of 875 studies...

Anthropogenic noise impacts are pervasive across taxa, ecosystems and the world. Here, we experimentally test the hypothesis that protecting vulnerable habitats from noise pollution can improve animal reproductive success. Using a season-long field manipulation with an established model system on the Great Barrier Reef, we demonstrate that limiting...

The understanding of swimming physiology and knowledge on the metabolic costs of swimming are important for assessing effects of environmental factors on migratory behavior. Swim tunnels are the most common experimental setups for measuring swimming performance and oxygen uptake rates in fishes; however, few can realistically simulate depth and the...

Wildlife health assessments help identify populations at risk of starvation, disease, and decline from anthropogenic impacts on natural habitats. We conducted an overview of available health assessment studies in noncaptive vertebrates and devised a framework to strategically integrate health assessments in population monitoring. Using a systematic...

In fishes, swimming performance is considered an important metric to measure fitness, dispersal and migratory abilities. The swimming performance of individual larval fishes is often integrated into models to make inferences on how environmental parameters affect population-level dynamics (e.g. connectivity). However, little information exists rega...

Parasites can account for a substantial proportion of the biomass in marine communities. As such, parasites play a significant ecological role in ecosystem functioning via host interactions. Unlike macropredators, such as large piscivores, micropredators rarely cause direct mortality. Rather, micropredators impose an energetic tax, thus significant...

Physiological measures can help to identify environmental thresholds that constrain organismal-level performance. Relating these thresholds, in a cause-and-effect manner, to long-term changes in the vital rates (e.g. growth, survival, reproduction) of wild populations has the potential to generate robust science advice needed to support conservatio...

Marine ectotherms are often sensitive to thermal stress, and certain life stages can be particularly vulnerable (e.g., larvae or spawners). In this study, we investigated the critical thermal maxima (CTmax) of larval and early juvenile life stages of three tropical marine fishes (Acanthochromis polyacanthus, Amphiprion melanopus, and Lates calcarif...

The larval phase of marine teleost fishes is characterized by important morphological and physiological modifications. Many of these modifications improve the larvae’s ability to swim, which satisfies a suite of crucial biological and ecological functions. Indeed, larval fish swimming performance has been considered a good proxy for overall conditi...

The intricate relationship between metabolism and growth is still largely unexplored in early life stages of fish. In the present study, two experiments were conducted to explore how standard metabolic rate (SMR) of Atlantic herring (Clupea harengus) larvae was related to differences in body size, growth rate and feeding environment. In two of the...

Coral reef fishes, like many other marine organisms, are affected by anthropogenic stressors such as fishing and pollution and, owing to climate change, are experiencing increasing water temperatures and ocean acidification. Against the backdrop of these various stressors, a mechanistic understanding of processes governing individual organismal per...

Increases in swimming ability have a profound influence on larval fish growth and survival by increasing foraging success, predator avoidance and the ability to favorably influence transport. Understanding how development and environmental factors combine to influence swimming performance in aquatic organisms is particularly important during the tr...

The year-class success of Atlantic herring (Clupea harengus) spawning in the autumn/winter in the North Sea (NSAS stock) and in the spring in the western Baltic Sea (WBSS) appears driven by prey match-mismatch dynamics affecting the survival of larvae during the first weeks of life. To better understand and model the consequences of prey match-mism...

This study investigated effects of microalgae (Rhodomonas baltica) and heterotrophic protists (Oxyrrhis marina) on the daily growth, activity, condition and feeding success of Atlantic herring (Clupea harengus) larvae from hatch, through the end of the endogenous (yolk sac) period. Yolk sac larvae were reared in the presence and absence of micropla...

Little is known regarding the swimming ability of the larvae of European plaice (Pleuronectes platessa) in relation to changes in total length (TL), dry weight (DW) and developmental stage, which is surprising given the importance of transport processes to the recruitment dynamics of this species in the North Sea and elsewhere. We investigated onto...