scholarly journals Ocean acidification boosts reproduction in fish via indirect effects

PLoS Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. e3001033
Author(s):  
Ivan Nagelkerken ◽  
Tiphaine Alemany ◽  
Julie M. Anquetin ◽  
Camilo M. Ferreira ◽  
Kim E. Ludwig ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Indirect Effects ◽  
Energy Levels ◽  
Reproductive Investment ◽  
Energy Budgets ◽  
Rocky Reef ◽  
Negative Effects ◽  
Species Population ◽  
In The Wild ◽  
Physiological Homeostasis

Ocean acidification affects species populations and biodiversity through direct negative effects on physiology and behaviour. The indirect effects of elevated CO2 are less well known and can sometimes be counterintuitive. Reproduction lies at the crux of species population replenishment, but we do not know how ocean acidification affects reproduction in the wild. Here, we use natural CO2 vents at a temperate rocky reef and show that even though ocean acidification acts as a direct stressor, it can indirectly increase energy budgets of fish to stimulate reproduction at no cost to physiological homeostasis. Female fish maintained energy levels by compensation: They reduced activity (foraging and aggression) to increase reproduction. In male fish, increased reproductive investment was linked to increased energy intake as mediated by intensified foraging on more abundant prey. Greater biomass of prey at the vents was linked to greater biomass of algae, as mediated by a fertilisation effect of elevated CO2 on primary production. Additionally, the abundance and aggression of paternal carers were elevated at the CO2 vents, which may further boost reproductive success. These positive indirect effects of elevated CO2 were only observed for the species of fish that was generalistic and competitively dominant, but not for 3 species of subordinate and more specialised fishes. Hence, species that capitalise on future resource enrichment can accelerate their reproduction and increase their populations, thereby altering species communities in a future ocean.

scholarly journals Ocean acidification alters fish–jellyfish symbiosis

2016 ◽  
Vol 283 (1833) ◽  
pp. 20161146 ◽  
Author(s):  
Ivan Nagelkerken ◽  
Kylie A. Pitt ◽  
Melchior D. Rutte ◽  
Robbert C. Geertsma
Keyword(s):  
Ocean Acidification ◽  
Greenhouse Gas Emission ◽  
Juvenile Fish ◽  
Open Water ◽  
Control Fish ◽  
Negative Effects ◽  
Symbiotic Relationships ◽  
Individual Fitness ◽  
Species Population ◽  
Business As Usual

Symbiotic relationships are common in nature, and are important for individual fitness and sustaining species populations. Global change is rapidly altering environmental conditions, but, with the exception of coral–microalgae interactions, we know little of how this will affect symbiotic relationships. We here test how the effects of ocean acidification, from rising anthropogenic CO 2 emissions, may alter symbiotic interactions between juvenile fish and their jellyfish hosts. Fishes treated with elevated seawater CO 2 concentrations, as forecast for the end of the century on a business-as-usual greenhouse gas emission scenario, were negatively affected in their behaviour. The total time that fish (yellowtail scad) spent close to their jellyfish host in a choice arena where they could see and smell their host was approximately three times shorter under future compared with ambient CO 2 conditions. Likewise, the mean number of attempts to associate with jellyfish was almost three times lower in CO 2 -treated compared with control fish, while only 63% (high CO 2 ) versus 86% (control) of all individuals tested initiated an association at all. By contrast, none of three fish species tested were attracted solely to jellyfish olfactory cues under present-day CO 2 conditions, suggesting that the altered fish–jellyfish association is not driven by negative effects of ocean acidification on olfaction. Because shelter is not widely available in the open water column and larvae of many (and often commercially important) pelagic species associate with jellyfish for protection against predators, modification of the fish–jellyfish symbiosis might lead to higher mortality and alter species population dynamics, and potentially have flow-on effects for their fisheries.

Negative effects of ocean acidification on two crustose coralline species using genetically homogeneous samples

2014 ◽  
Vol 94 ◽  
pp. 1-6 ◽  
Author(s):  
Aki Kato ◽  
Mana Hikami ◽  
Naoki H. Kumagai ◽  
Atsushi Suzuki ◽  
Yukihiro Nojiri ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Negative Effects

scholarly journals Shell mineralogy of a foundational marine species, Mytilus californianus, over half a century in a changing ocean

2021 ◽  
Vol 118 (3) ◽  
pp. e2004769118
Author(s):  
Elizabeth M. Bullard ◽  
Ivan Torres ◽  
Tianqi Ren ◽  
Olivia A. Graeve ◽  
Kaustuv Roy
Keyword(s):  
Ocean Acidification ◽  
Historical Data ◽  
Mineralogical Composition ◽  
Marine Species ◽  
Mytilus Californianus ◽  
Negative Effects ◽  
Saturation State ◽  
Long Term Changes ◽  
Time Periods

Anthropogenic warming and ocean acidification are predicted to negatively affect marine calcifiers. While negative effects of these stressors on physiology and shell calcification have been documented in many species, their effects on shell mineralogical composition remains poorly known, especially over longer time periods. Here, we quantify changes in the shell mineralogy of a foundation species, Mytilus californianus, under 60 y of ocean warming and acidification. Using historical data as a baseline and a resampling of present-day populations, we document a substantial increase in shell calcite and decrease in aragonite. These results indicate that ocean pH and saturation state, not temperature or salinity, play a strong role in mediating the shell mineralogy of this species and reveal long-term changes in this trait under ocean acidification.

scholarly journals Nitrogen enrichment offsets direct negative effects of ocean acidification on a reef-building crustose coralline alga

2018 ◽  
Vol 14 (7) ◽  
pp. 20180371 ◽  
Author(s):  
Maggie D. Johnson ◽  
Robert C. Carpenter
Keyword(s):  
Ocean Acidification ◽  
Nutrient Enrichment ◽  
Multiple Stressors ◽  
Crustose Coralline Alga ◽  
Nitrogen Enrichment ◽  
Coralline Alga ◽  
Ambient Conditions ◽  
Negative Effects ◽  
Near Shore ◽  
Near Future

Ocean acidification (OA) and nutrient enrichment threaten the persistence of near shore ecosystems, yet little is known about their combined effects on marine organisms. Here, we show that a threefold increase in nitrogen concentrations, simulating enrichment due to coastal eutrophication or consumer excretions, offset the direct negative effects of near-future OA on calcification and photophysiology of the reef-building crustose coralline alga, Porolithon onkodes . Projected near-future pCO 2 levels (approx. 850 µatm) decreased calcification by 30% relative to ambient conditions. Conversely, nitrogen enrichment (nitrate + nitrite and ammonium) increased calcification by 90–130% in ambient and high pCO 2 treatments, respectively. pCO 2 and nitrogen enrichment interactively affected instantaneous photophysiology, with highest relative electron transport rates under high pCO 2 and high nitrogen. Nitrogen enrichment alone increased concentrations of the photosynthetic pigments chlorophyll a , phycocyanin and phycoerythrin by approximately 80–450%, regardless of pCO 2 . These results demonstrate that nutrient enrichment can mediate direct organismal responses to OA. In natural systems, however, such direct benefits may be counteracted by simultaneous increases in negative indirect effects, such as heightened competition. Experiments exploring the effects of multiple stressors are increasingly becoming important for improving our ability to understand the ramifications of local and global change stressors in near shore ecosystems.

scholarly journals Coasting in live-bearing fish: the drag penalty of being pregnant

2019 ◽  
Vol 16 (151) ◽  
pp. 20180714 ◽  
Author(s):  
Elsa M. Quicazan-Rubio ◽  
Johan L. van Leeuwen ◽  
Klaas van Manen ◽  
Mike Fleuren ◽  
Bart J. A. Pollux ◽  
...  
Keyword(s):  
Swimming Performance ◽  
Three Dimensional ◽  
Reproductive Investment ◽  
Body Volume ◽  
Negative Effects ◽  
Bending Performance ◽  
Body Drag ◽  
Wetted Area ◽  
Three Dimensional Models ◽  
Different Levels

Swimming performance of pregnant live-bearing fish is presumably constrained by the additional drag associated with the reproductive burden. Yet, it is still unclear how and to what extent the reproductive investment affects body drag of the females. We examined the effect of different levels of reproductive investment on body drag. The biggest measured increase in body volume due to pregnancy was about 43%, linked to a wetted area increase of about 16% and 69% for the frontal area. We printed three-dimensional models of live-bearing fish in a straight body posture representing different reproductive allocation (RA) levels. We measured the drag and visualized the flow around these models in a flow tunnel at different speeds. Drag grew in a power fashion with speed and exponentially with the increase of RA, thus drag penalty for becoming thicker was relatively low for low speeds compared to high ones. We show that the drag increase with increasing RA was most probably due to bigger regions of flow separation behind the enlarged belly. We suggest that the rising drag penalty with an increasing RA, possibly together with pregnancy-related negative effects on muscle- and abdominal bending performance, will reduce the maximum swimming speed.

scholarly journals Bidirectional cyclical flows increase energetic costs of station holding for a labriform swimming fish, Cymatogaster aggregata

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Sarah M Luongo ◽  
Andreas Ruth ◽  
Connor R Gervais ◽  
Keith E Korsmeyer ◽  
Jacob L Johansen ◽  
...  
Keyword(s):  
Steady Flow ◽  
Flow Direction ◽  
Energy Budgets ◽  
Constant Flow ◽  
Energetic Costs ◽  
Mean Velocity ◽  
Unidirectional Flow ◽  
In The Wild ◽  
Additional Costs ◽  
Temperate Fish

Abstract Wave-induced surge conditions are found in shallow marine ecosystems worldwide; yet, few studies have quantified how cyclical surges may affect free swimming animals. Here, we used a recently adapted respirometry technique to compare the energetic costs of a temperate fish species (Cymatogaster aggregata) swimming against a steady flow versus cyclical unidirectional and bidirectional surges in which unsteady swimming (such as accelerating, decelerating and turning) occurs. Using oxygen uptake (ṀO2) as an estimate of energetic costs, our results reveal that fish swimming in an unsteady (i.e. cyclical) unidirectional flow showed no clear increase in costs when compared to a steady flow of the same average speed, suggesting that costs and savings from cyclical acceleration and coasting are near equal. Conversely, swimming in a bidirectional cyclical flow incurred significantly higher energetic costs relative to a steady, constant flow, likely due to the added cost of turning around to face the changing flow direction. On average, we observed a 50% increase in ṀO2 of fish station holding within the bidirectional flow (227.8 mg O2 kg−1 h−1) compared to a steady, constant flow (136.1 mg O2 kg−1 h−1) of the same mean velocity. Given wave-driven surge zones are prime fish habitats in the wild, we suggest the additional costs fish incur by station holding in a bidirectional cyclical flow must be offset by favourable conditions for foraging and reproduction. With current and future increases in abiotic stressors associated with climate change, we highlight the importance of incorporating additional costs associated with swimming in cyclical water flow in the construction of energy budgets for species living in dynamic, coastal habitats.

scholarly journals Reviews and Syntheses: Responses of coccolithophores to ocean acidification: a meta-analysis

2015 ◽  
Vol 12 (6) ◽  
pp. 1671-1682 ◽  
Author(s):  
J. Meyer ◽  
U. Riebesell
Keyword(s):  
Ocean Acidification ◽  
Dissolved Inorganic Carbon ◽  
Meta Analysis ◽  
Physiological Responses ◽  
Total Alkalinity ◽  
Adaptive Responses ◽  
Negative Effects ◽  
Ecological Fitness ◽  
Negative Effect ◽  
Gephyrocapsa Oceanica

Abstract. Concerning their sensitivity to ocean acidification, coccolithophores, a group of calcifying single-celled phytoplankton, are one of the best-studied groups of marine organisms. However, in spite of the large number of studies investigating coccolithophore physiological responses to ocean acidification, uncertainties still remain due to variable and partly contradictory results. In the present study we have used all existing data in a meta-analysis to estimate the effect size of future pCO2 changes on the rates of calcification and photosynthesis and the ratio of particulate inorganic to organic carbon (PIC / POC) in different coccolithophore species. Our results indicate that ocean acidification has a negative effect on calcification and the cellular PIC / POC ratio in the two most abundant coccolithophore species: Emiliania huxleyi and Gephyrocapsa oceanica. In contrast, the more heavily calcified species Coccolithus braarudii did not show a distinct response when exposed to elevated pCO2/reduced pH. Photosynthesis in Gephyrocapsa oceanica was positively affected by high CO2, while no effect was observed for the other coccolithophore species. There was no indication that the method of carbonate chemistry manipulation was responsible for the inconsistent results regarding observed responses in calcification and the PIC / POC ratio. The perturbation method, however, appears to affect photosynthesis, as responses varied significantly between total alkalinity (TA) and dissolved inorganic carbon (DIC) manipulations. These results emphasize that coccolithophore species respond differently to ocean acidification, both in terms of calcification and photosynthesis. Where negative effects occur, they become evident at CO2 levels in the range projected for this century in the case of unabated CO2 emissions. As the data sets used in this meta-analysis do not account for adaptive responses, ecological fitness and ecosystem interactions, the question remains as to how these physiological responses play out in the natural environment.

Energetics: the costs of living and reproducing for an individual cephalopod

1996 ◽  
Vol 351 (1343) ◽  
pp. 1083-1104 ◽  
Keyword(s):  
Specific Dynamic Action ◽  
Energy Budgets ◽  
Food Conversion ◽  
Laboratory Studies ◽  
Feeding Rates ◽  
Historical Factors ◽  
In The Wild ◽  
Excretion Rates ◽  
The Cost ◽  
Conversion Efficiencies

Cephalopods, like all other animals, have to decide how to allocate resources; maintenance processes, growth of somatic and reproductive tissues, and locomotor activity all have costs. We should like to be able to identify these costs and discover how efficiently cephalopods make use of the prey that they capture and digest. Cephalopods generally grow fast and mature rapidly; a first task is to determine how accurately laboratory studies reflect growth in the wild, because much of the information we need (such as food conversion efficiencies, excretion rates or the costs of locomotion) can be collected only from animals kept in the laboratory. Comparison of laboratory feeding and growth rates for octopods, sepioids and teuthoids with fisheries data suggests that data collected from cephalopods fed ad libitum in the laboratory may be used validly to construct energy budgets representative of individuals in the wild. The immediate cost of feeding (the specific dynamic action) has been thoroughly documented in Octopus , as has the longer-term elevation or depression of metabolic rate by feeding or starvation; it is assumed that similar costs will be found in squid. The cost of locomotion has been studied in both octopods and squid, but we have only limited data on how much time the animals spend moving, and how rapidly, in the wild. Excretory and faecal losses are assessed from laboratory studies, and maintenance costs estimated from feeding rates that just maintain body mass in the laboratory. Comparison of gross and net food conversion efficiencies suggest that squid convert food into tissues less efficiently than octopods, owing primarily to their greater time spent in locomotion. We present a representative series of energy budgets for octopods (based on Octopus ) and squids (based on Illex and Loligo ), for starving, feeding, migrating and maturing individuals. A major contrast is provided by Nautilus, which lives for ten or twenty years and grows only slowly. Finally we speculate on the possible biochemical and historical factors that may have limited the adaptive radiation of cephalopods, resulting in a group lacking herbivores, detritivores or filter-feeders but extremely successful as carnivores.

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