Feeding habits of range-shifting herbivores: tropical surgeonfishes in a temperate environment

A widely documented impact of ocean warming is the poleward shift in species’ distributions. This includes the global movement of tropical fishes into temperate rocky reefs. The ecological impacts of such range extensions are, however, largely unknown. We compared the feeding habits of herbivorous tropical surgeonfishes (Acanthuridae) to that of warm-temperate surgeonfishes near Sydney, Australia. The abundance of tropical surgeonfishes peaked during warmer months before they became locally extinct in winter. Comparisons of bite rates in the field between tropical (Acanthurus triostegus, Acanthurus dussumieri) and warm-temperate (Prionurus microlepidotus, Prionurus maculatus) surgeonfishes showed a significant effect of schooling, with both groups feeding most intensely in monospecific schools. In aquarium feeding trials, tropical surgeonfishes consumed more algae than their warm-temperate counterparts at both high and low temperatures (25 and 20°C), and had higher bite rates at 25°C than at 20°C. A. dussumieri also had significantly higher consumption rates on brown algal recruits at warmer temperatures. We further compared gut indices and jaw-lever ratios among the four focal species, and found no consistent pattern between tropical and warm-temperate fishes. This study suggests that the continued intrusion of tropical surgeonfishes in temperate reefs will result in increased herbivory, as a result of both higher herbivore abundance and higher consumption rates per capita by tropical species.

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Intraspecific variation in thermal tolerance differs between tropical and temperate fishes

Scientific Reports ◽

10.1038/s41598-021-00695-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

J. J. H. Nati ◽

M. B. S. Svendsen ◽

S. Marras ◽

S. S. Killen ◽

J. F. Steffensen ◽

...

Keyword(s):

Climate Change ◽

Global Warming ◽

Intraspecific Variation ◽

Fish Species ◽

Thermal Tolerance ◽

Evolutionary History ◽

Ecological Impacts ◽

Temperate Species ◽

Tropical Species ◽

Upper Thermal Tolerance

AbstractHow ectothermic animals will cope with global warming is a critical determinant of the ecological impacts of climate change. There has been extensive study of upper thermal tolerance limits among fish species but how intraspecific variation in tolerance may be affected by habitat characteristics and evolutionary history has not been considered. Intraspecific variation is a primary determinant of species vulnerability to climate change, with implications for global patterns of impacts of ongoing warming. Using published critical thermal maximum (CTmax) data on 203 fish species, we found that intraspecific variation in upper thermal tolerance varies according to a species’ latitude and evolutionary history. Overall, tropical species show a lower intraspecific variation in thermal tolerance than temperate species. Notably, freshwater tropical species have a lower variation in tolerance than freshwater temperate species, which implies increased vulnerability to impacts of thermal stress. The extent of variation in CTmax among fish species has a strong phylogenetic signal, which may indicate a constraint on evolvability to rising temperatures in tropical fishes. That is, in addition to living closer to their upper thermal limits, tropical species may have higher sensitivity and lower adaptability to global warming compared to temperate counterparts. This is evidence that freshwater tropical fish communities, worldwide, are especially vulnerable to ongoing climate change.

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New Evidence of Marine Fauna Tropicalization off the Southwestern Iberian Peninsula (Southwest Europe)

Diversity ◽

10.3390/d11040048 ◽

2019 ◽

Vol 11 (4) ◽

pp. 48 ◽

Cited By ~ 5

Author(s):

João Encarnação ◽

Pedro Morais ◽

Vânia Baptista ◽

Joana Cruz ◽

Maria Teodósio

Keyword(s):

Iberian Peninsula ◽

Seawater Temperature ◽

Tropical Species ◽

Marine Fauna ◽

Aquatic Fauna ◽

Hermodice Carunculata ◽

Comprehensive Survey ◽

Poleward Shift ◽

New Evidence ◽

Potential Public Health

Climate change and the overall increase of seawater temperature are causing a poleward shift in species distribution, which includes a phenomenon described as the tropicalization of temperate regions. This work aims to report the first records of four species off the southwestern Iberian Peninsula, namely, the oceanic puffer Lagocephalus lagocephalus (Linnaeus, 1758), the Madeira rockfish Scorpaena maderensis Valenciennes, 1833, the ornate wrasse Thalassoma pavo (Linnaeus, 1758), and the bearded fireworm Hermodice carunculata (Pallas, 1766). These last three species, along with other occurrences of aquatic fauna and flora along the Portuguese coast, reveal an ongoing process of poleward expansion of several species, which urgently necessitates a comprehensive survey along the entire Iberian Peninsula. The putative origins of these subtropical and tropical species off continental Portugal are discussed, as well as the potential public health problems that two of the four reported species may cause.

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Taking a deeper look: Quantifying the differences in fish assemblages between shallow and mesophotic temperate rocky reefs

10.1101/449959 ◽

2018 ◽

Author(s):

Joel Williams ◽

Alan Jordan ◽

David Harasti ◽

Peter Davies ◽

Tim Ingleton

Keyword(s):

Species Richness ◽

Linear Models ◽

Fish Assemblages ◽

Habitat Type ◽

Rocky Reefs ◽

Temperate Reefs ◽

Video Systems ◽

Parsimonious Model ◽

Using Data ◽

Species Richness And Abundance

AbstractThe spatial distribution of a species assemblage is often determined by habitat and climate. In the marine environment, depth can become an important factor as degrading light leads to changes in the biological habitat structure. To date, much of the focus of ecological fish research has been based on reefs in less than 40 m with little research on the ecological role of mesophotic reefs. We deployed baited remote underwater stereo video systems (stereo-BRUVS) on temperate reefs in two depth categories: shallow (20-40m) and mesophotic (80-120m), off Port Stephens, Australia. Sites were selected using data collected by swath acoustic sounder to ensure stereo-BRUVS were deployed on reef. The sounder also provided rugosity, slope and relief data for each stereo-BRUVS deployment. Multivariate analysis indicates that there are significant differences in the fish assemblages between shallow and mesophotic reefs, primarily driven by Ophthalmolepis lineolatus and Notolabrus gymnogenis only occurring on shallow reefs and schooling species of fish that were unique to each depth category: Atypichthys strigatus on shallow reefs and Centroberyx affinis on mesophotic reefs. While shallow reefs had a greater species richness and abundance of fish when compared to mesophotic reefs, mesophotic reefs hosted the same species richness of fishery targeted species. Chrysophrys auratus (pink snapper) and Nemodactylus douglassii (grey morwong) are two highly targeted species in this region. While C. auratus was numerically more abundant on shallow reefs, mesophotic reefs provide habitat for larger fish. In comparison, N. douglassii were evenly distributed across all sites sampled. Generalized linear models revealed that depth and habitat type provided the most parsimonious model for predicting the distribution of C. auratus, while habitat type alone best predicted the distribution of N. douglassii. These results demonstrate the importance of mesophotic reefs to fishery targeted species and therefore have implications for informing the management of these fishery resources on shelf rocky reefs.

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On the behaviour of barnacles III. Further observations on the influence of temperature and age on cirral activity

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315400016830 ◽

1957 ◽

Vol 36 (2) ◽

pp. 323-334 ◽

Cited By ~ 40

Author(s):

A. J. Southward

Keyword(s):

Age Groups ◽

Wide Distribution ◽

Tropical Species ◽

Growth Rings ◽

Temperature Range ◽

Wide Range ◽

Different Temperatures ◽

Warm Temperate ◽

Northern Species ◽

Active Can

The range of temperature over which the cirri were active, and the frequency of beating of the cirri at different temperatures were measured in a further five species of barnacles from a variety of habitats. In three of the species the temperature range and frequency of cirral beat were related to the geographical distribution of the species. The tropical and warm temperate species Balanus amphitrite was active at higher temperatures, and showed a greater frequency of beating than the northern species B. balanus; conversely, the latter was active to much lower temperatures than JB. amphitrite. The species with the widest geographical range, B. improvisus, showed cirral activity over the widest range of temperatures, although its behaviour at high temperatures was similar to that of the related species B. amphitrite. It is suggested that B. improvisus is a tropical species that has adapted itself to colder climates; its tolerance of a wide range of temperatures may be associated with its tolerance of low salinities.The stalked barnacle Lepas anatifera showed too restricted a temperature range for its supposed world-wide distribution, and it is suggested that the species may contain physiological races adapted to different climates. The extremely restricted range of temperatures over which the cirri of the deepsea barnacle Hexelasma hirsutum were active can be correlated with the almost uniform temperature conditions at great depths.In B. balanus age-groups can be clearly distinguished by growth rings on the shell, and the cirral frequency was found to be slower in the older specimens. Even slower cirral beating was found in some starved specimens.

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The tropicalization of temperate marine ecosystems: climate-mediated changes in herbivory and community phase shifts

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2014.0846 ◽

2014 ◽

Vol 281 (1789) ◽

pp. 20140846 ◽

Cited By ~ 383

Author(s):

Adriana Vergés ◽

Peter D. Steinberg ◽

Mark E. Hay ◽

Alistair G. B. Poore ◽

Alexandra H. Campbell ◽

...

Keyword(s):

Phase Shift ◽

Biotic Interactions ◽

Phase Shifts ◽

Tropical Fish ◽

Tropical Species ◽

Ecological Communities ◽

Marine Systems ◽

Boundary Currents ◽

Temperate Reefs ◽

Fish Herbivory

Climate-driven changes in biotic interactions can profoundly alter ecological communities, particularly when they impact foundation species. In marine systems, changes in herbivory and the consequent loss of dominant habitat forming species can result in dramatic community phase shifts, such as from coral to macroalgal dominance when tropical fish herbivory decreases, and from algal forests to ‘barrens’ when temperate urchin grazing increases. Here, we propose a novel phase-shift away from macroalgal dominance caused by tropical herbivores extending their range into temperate regions. We argue that this phase shift is facilitated by poleward-flowing boundary currents that are creating ocean warming hotspots around the globe, enabling the range expansion of tropical species and increasing their grazing rates in temperate areas. Overgrazing of temperate macroalgae by tropical herbivorous fishes has already occurred in Japan and the Mediterranean. Emerging evidence suggests similar phenomena are occurring in other temperate regions, with increasing occurrence of tropical fishes on temperate reefs.

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Prey preferences, consumption rates and predation effects of Asian shore crabs (Hemigrapsus takanoi) in comparison to native shore crabs (Carcinus maenas) in northwestern Europe

Marine Biodiversity ◽

10.1007/s12526-021-01207-7 ◽

2021 ◽

Vol 51 (5) ◽

Author(s):

Annika Cornelius ◽

Katerina Wagner ◽

Christian Buschbaum

Keyword(s):

Feeding Behavior ◽

Wadden Sea ◽

Feeding Habits ◽

Carcinus Maenas ◽

Shore Crab ◽

Crab Species ◽

Blue Mussels ◽

Pacific Oysters ◽

Shore Crabs ◽

Consumption Rates

AbstractThe Asian brush-clawed shore crab Hemigrapsus takanoi was introduced to the northern Wadden Sea (southeastern North Sea) in 2009 and now represents one of the most abundant brachyuran crab species. Abundance studies revealed an increase of mean crab densities on mixed reefs of native blue mussels (Mytilus edulis) and Pacific oysters (Magallana gigas) from 18 individuals m−2 in 2011 to 216 individuals m−2 in 2020. Despite its current high densities only little is known about the feeding habits of H. takanoi, its effects on prey populations and on the associated community in the newly invaded habitat. We summarize results of individual field and laboratory experiments that were conducted to assess feeding habits and consumption effects caused by Asian brush-clawed shore crabs and, additionally, compare the feeding ecology of H. takanoi with the one of the native shore crab Carcinus maenas. Field experiments manipulating crab densities revealed that both crab species affected the recruitment success of blue mussels, Pacific oysters and Australian barnacles (Austrominius modestus) with highest number of recruits at crab exclusion. However, endobenthic polychaetes within the reefs were differently affected. Only the native C. maenas caused a significant reduction in polychaete densities, whereas the introduced H. takanoi had no effect. Additional comparative laboratory studies revealed that single C. maenas consume more juvenile blue mussels than Asian brush-clawed shore crabs of the same size class. When offering amphipods as a mobile prey species, we found the same pattern with higher consumption rates by C. maenas than by H. takanoi. For Asian but not for native shore crabs, we detected a sex-dependent feeding behavior with male H. takanoi preferring blue mussels, while females consumed more amphipods. Considering mean crab densities and feeding behavior, our results suggest that despite lower consumption rates of single crabs, Asian brush-clawed shore crabs can cause stronger impacts on prey organisms than the native C. maenas, because H. takanoi exceeds their densities manifold. A strong impact of the invader on prey populations is supported by low amphipod occurrence at sites where H. takanoi density is high in the study area. Thus, the introduced Asian brush-clawed shore crab is an additional consumer with significant effects on the associated community of mixed reefs of mussels and oysters in the Wadden Sea.

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Soundscapes of natural and artificial temperate reefs: similar temporal patterns but distinct spectral content

Marine Ecology Progress Series ◽

10.3354/meps13434 ◽

2020 ◽

Vol 649 ◽

pp. 35-51

Author(s):

RV Van Hoeck ◽

AB Paxton ◽

DR Bohnenstiehl ◽

JC Taylor ◽

FJ Fodrie ◽

...

Keyword(s):

Sound Production ◽

Spectral Characteristics ◽

Temporal Patterns ◽

Marine Species ◽

Artificial Reefs ◽

Spectral Content ◽

The North ◽

Rocky Reefs ◽

Temperate Reefs ◽

Naturally Occurring

Marine soundscapes often differ among habitats; however, relatively little is known about whether soundscapes on naturally occurring habitats differ from soundscapes on human-made structures. To address this knowledge gap, we investigated whether temporal and spectral characteristics of biological sound production differ between natural and artificial offshore reefs. Specifically, we analyzed recordings from 5 week-long hydrophone deployments on 2 natural rocky reefs and 2 artificial reefs on the North Carolina, USA, continental shelf. Analysis of sound pressure levels (SPLs) on hourly and seasonal scales revealed similar temporal patterns between the reef types. These patterns were largely driven by 4 dominant fish vocalizers with seasonal chorusing patterns, including a toadfish Opsanus sp. Despite similar temporal patterns within reef types, soundscape spectral content was more similar within than between reef types, especially during the April deployment, which had the most acoustic activity. Our findings suggest that the soundscapes of shipwreck artificial reefs may differ from the soundscapes of natural rocky reefs, possibly due to differing community composition. As sound plays an important role in the navigation and settlement of many marine species, soundscape differences between natural and artificial habitats could affect ecosystem function through species behavior and interactions.

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“Environmentalism of the poor”: the Tipaimukh Dam, ecological disasters and environmental resistance beyond borders

Bandung Journal of the Global South ◽

10.1186/s40728-016-0030-5 ◽

2016 ◽

Vol 3 (1) ◽

pp. 1-16 ◽

Cited By ~ 5

Author(s):

Md Saidul Islam ◽

Md Nazrul Islam

Keyword(s):

Ecological Impacts ◽

Policy Recommendations ◽

Construction Work ◽

Indian Government ◽

Environmental Resistance ◽

The Poor ◽

Barak River ◽

North Eastern ◽

Global Movement ◽

Eastern Border

The Indian government recently resumed the construction of the Tipaimukh Dam on the Barak River just 1 km north of Bangladesh’s north-eastern border. The construction work was stalled in March 2007 in the wake of massive protests from within and outside India. Experts have argued that the Dam, when completed, would cause colossal disasters to Bangladesh and India, with the former being vastly affected: the Dam would virtually dry up the Surma and Kushiara, two important rivers for Bangladesh. Therefore, this controversial Dam project has generated immense public discontents leading to wider mass-movements in Bangladesh, India, and around the world. The movement has taken various forms, ranging from simple protests to a submission of a petition to the United Nations. Drawing on the “environmentalism of the poor” as a conceptual metaphor, the article examines this global movement to show how environmental resistance against the Tipaimukh Dam has transcended national borders and taken on a transnational form by examining such questions as: who is protesting, why, in what ways, and with what effects. In order to elucidate the impending social and ecological impacts, which would potentially disrupt communities in South Asia, the paper offers some pragmatic policy recommendations that also seek to augment social mobility in the region.

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The feeding habits of the endemic Remo flounder, Oncopterus darwinii (Actinopterygii: Pleuronectidae), in an exposed sandy beach’s surf zone in southern Brazil

Zoologia (Curitiba) ◽

10.3897/zoologia.35.e15038 ◽

2018 ◽

Vol 35 ◽

pp. 1-8 ◽

Cited By ~ 1

Author(s):

Fábio R. Lameiro ◽

Mario V. Condini ◽

Cintia P. Brito ◽

João P. Vieira

Keyword(s):

Sandy Beach ◽

Surf Zone ◽

Feeding Habits ◽

Sandy Beaches ◽

Early Summer ◽

Nursery Ground ◽

Warm Temperate Zone ◽

Index Of Relative Importance ◽

One Year ◽

Warm Temperate

The Remo flounder, Oncopterusdarwinii Steindachner, 1874 is a small Pleuronectidae (~ 250 mm TL) distributed in the warm-temperate zone from Santa Catarina (28°S – Brazil) to the Gulf of San Matías (42°S – Argentina). We studied the occurrence and diet of juveniles of this flatfish (85% < 100 mm TL) for one year (August 2009 to July 2010) in a southern Brazilian sandy beach. Individuals were much more common in spring and early summer than in the other seasons. Of the 758 individuals analyzed, only 69 (9.1%) were found with empty stomachs. The Remo flounder fed predominantly on small crustaceans (gammarid amphipods, mysids and the hipiidae Emeritabrasiliensis Schmitt, 1935) and no seasonal differences were found in the composition of the diet of this flatfish. However, variations in the Index of Relative Importance (IRI) were found among seasons, which most likely can be explained by a decrease in the availability of favored food items throughout the year. The pattern of distribution of O.darwinii indicates that southern Brazilian sandy beaches are used as nursery ground for this species.

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Tropicalization of temperate reef fish communities depends on urchin herbivory and thermal response diversity

10.22541/au.160191033.32038352/v2 ◽

2021 ◽

Author(s):

Jasmin Schuster ◽

Rick Stuart-Smith ◽

Graham Edgar ◽

Amanda Bates

Keyword(s):

Fish Communities ◽

Thermal Response ◽

Ecological Change ◽

Biological Communities ◽

Response Diversity ◽

Temperate Reef ◽

Temperate Reefs ◽

Species Pools ◽

Temperate Reef Fish ◽

Warm Temperate

Global declines in structurally complex habitats are reshaping both land and seascapes in directions that affect biological communities’ responses to warming. Here, we test whether widespread loss of kelp habitats through sea urchin overgrazing systematically changes warming sensitivity of fish communities. Community thermal affinity shifts related to habitat were assessed by simulating and comparing fish communities from 2,271 surveys across 15 ecoregions. We find that fishes in kelp and urchin barrens differ in realized thermal affinities and range sizes, but only in regions where species pools have high variability in species’ thermal affinities. Barrens on warm-temperate reefs host relatively more warm-affinity fish species than neighbouring kelp beds, highlighting acceleration of tropicalization processes facilitated by urchin herbivory. By contrast, proportionally more cool-affinity fishes colonize barrens at high temperate latitudes, contributing to community lags with ocean warming in these regions. Our findings implicate urchins as drivers of ecological change, in part by affecting biological resilience to warming.

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