Ocean Acidification Research Articles

Transcriptomic responses in the nervous system and correlated behavioural changes of a cephalopod exposed to ocean acidification

BackgroundThe nervous system is central to coordinating behavioural responses to environmental change, likely including ocean acidification (OA). However, a clear understanding of neurobiological responses to OA is lacking, especially for marine invertebrates.ResultsWe evaluated the transcriptomic response of the central nervous system (CNS) and eyes of the two-toned pygmy squid (Idiosepius pygmaeus) to OA conditions, using a de novo transcriptome assembly created with long read PacBio ISO-sequencing data. We then correlated patterns of gene expression with CO2 treatment levels and OA-affected behaviours in the same individuals. OA induced transcriptomic responses within the nervous system related to various different types of neurotransmission, neuroplasticity, immune function and oxidative stress. These molecular changes may contribute to OA-induced behavioural changes, as suggested by correlations among gene expression profiles, CO2 treatment and OA-affected behaviours.ConclusionsThis study provides the first molecular insights into the neurobiological effects of OA on a cephalopod and correlates molecular changes with whole animal behavioural responses, helping to bridge the gaps in our knowledge between environmental change and animal responses.

Impact of ocean acidification on microzooplankton grazing dynamics

This study examines the potential impacts of projected atmospheric carbon dioxide (pCO2) levels reaching 800 ppm by the end of the century, focusing on ocean acidification effects on marine ecosystems in the coastal areas of Bohai. We investigated how acidification affects the grazing patterns of microzooplankton using dilution techniques and ecophysiological methods. Our findings indicate that acidic conditions shift the phytoplankton community structure, changing dominant species. Elevated CO2 concentrations reduced grazing pressure on phytoplankton, with less steep declines in growth rates at 800 ppm CO2 (spring: 2.43 d−1 vs. 2.16 d−1, summer: −0.46 d−1 vs. −0.73 d−1, autumn: −0.45 d−1 vs. −0.90 d−1) and significant decreases in grazing pressure percentages (%Pp from 0.84 to 0.58 and %Pi from 0.64 to 0.46). Short-term acid exposure significantly increased superoxide dismutase activity in both microplankton (from 0.03 to 0.08 U mg−1, p<0.01) and nanoplankton (from 0.05 to 0.09 U mg−1, p<0.001), indicating an adaptive response to oxidative stress. These results highlight that elevated CO2 levels primarily boost phytoplankton growth by reducing microzooplankton grazing pressure, resulting in higher growth rates and a shift towards smaller-sized phytoplankton, reflecting complex short-term ecological responses to acidification. Further research is needed to understand the long-term effects of ocean acidification on microzooplankton and their role in marine secondary productivity.

Exploring ocean pH dynamics via a mathematical modeling with the Caputo fractional derivative

AbstractGlobal warming is a complex problem with far-reaching global implications. One of its notable repercussions is the escalation of $$CO_2$$ C O 2 levels in the atmosphere, resulting in the phenomenon known as Ocean Acidification (OA). In this research, we have established a correlation between four key factors: marine species, human population, $$CO_2$$ C O 2 levels, and ocean pH. By formulating a Caputo fractional differential equation, we investigated the dynamics of these variables to evaluate the significance of this climatic phenomenon. The model analysis reveals that the rise in anthropogenic $$CO_2$$ C O 2 emissions causes a reduction in the ocean’s pH level and increases OA. This process, in turn, decreases the ocean’s ability to absorb $$CO_2$$ C O 2 , making it less effective in mitigating climate change. In this study, it was demonstrated that elevated levels of $$CO_2$$ C O 2 result in a reduction in pH levels, which in turn causes a decrease in the population of marine species that play a critical role in numerous economic sectors such as tourism, aquaculture, and fisheries. Moreover, we conducted a comprehensive analysis of the influence exerted by the intrinsic growth rate of the human population. We examined various theoretical aspects, including the assessment of existence and uniqueness. Numerical simulations are carried out to illustrate the effect of key parameters on the dynamics of the system using the generalized Adams–Bashforth–Moulton method.

Spectrophotometrically derived seawater CO2‐system assessments: Parameter calculations using pH do not require measurements at standard temperatures

AbstractThe temperature range of Earth's open‐ocean waters is roughly 0–30°C, yet our understanding of the seawater carbon dioxide (CO2) system is largely derived from analyses conducted within a narrow temperature range (e.g., laboratory temperature of 20°C or 25°C). Herein, we address two aspects of open‐ocean CO2‐system measurements and modeling: (1) a highly precise spectrophotometric technique is used to determine bicarbonate dissociation constants (K2) in seawater at temperatures as low as 3°C and (2) a cruise dataset uniquely including total scale pH measurements at two temperatures is used for CO2‐system internal consistency comparisons at 12°C and 25°C. Our pK2 parameterization (where pK = −log K) is applicable for broad ranges of salinity (20 ≤ SP ≤ 40) and temperature (3°C ≤ t ≤ 35°C). Our CO2‐system internal consistency evaluation (comparison of measured and calculated CO2‐system parameters) utilized data obtained during NOAA's 2021 West Coast Ocean Acidification Cruise: total alkalinity (TA), total dissolved inorganic carbon (DIC), pH measured at 25°C, and pH measured at 12°C (n = 265). Results demonstrate that, relative to calculations utilizing the TA, DIC pair, agreement between measured and calculated parameters is improved when either TA or DIC is paired with pH measurements at either temperature. Calculations of CO2 fugacity (fCO2) and aragonite saturation state (Ωar) using pH measurements made at 25°C or 12°C (paired with either TA or DIC) are statistically indistinguishable. Results also suggest that the temperature dependence of current CO2‐system dissociation constants need further refinement.

Patterns of carbonate chemistry in mangroves of the Northern Persian Gulf

The mangroves located in the Northern Persian Gulf are reeling from anthropogenic pressures including from intense industrial activities (Pars Special Economic Energy Zone-PSEEZ). Given the unique geographical location of these mangroves, understanding the initial basis of seawater carbonate chemistry is key to link with global patterns of coastal ocean carbonate dynamics. In this study, water samples were collected from pre-designated stations representing the mangrove forest and nearshore water namely Nayband, Mel-e-Gonzeh and Bardestan of the Persian Gulf in September of 2016. Based on extensive carbonate chemistry measurements, the results show that the pCO2 at the Nayband site (13217.9±5841.5 µatm) was significantly higher than the other two sites (Mel-e-Gonzeh: 416.4±49.3 µatm and Bardestan: 294.3±95.0 µatm) while pH (6.92±0.18) was significantly lower than the two other sites (Mel-e-Gonzeh: 8.18±0.02, Bardestan: 8.26±0.04). The observed increase of pCO2 and decrease of surface water pH at the Nayband site compared to other two sites may have due to the emission of CO2 originating from oil and gas refining facilities located PSEEZ. Moreover, surface water in Nayband was undersaturated with respect to aragonite (Ωarg<1) and supersaturated (Ωarg>1) in case of the Mel-e-Gonzeh and Bardestan sites. This study although preliminary provides much-needed baseline information to address issues of changing carbonate chemistry and can help towards understanding the basis of coastal ocean acidification.

New Insights into Calcite Dissolution Mechanisms under Water, Proton, or Carbonic Acid-Dominated Conditions.

Carbonate minerals are ubiquitous in nature, and their dissolution impacts many environmentally relevant processes including preferential flow during geological carbon sequestration, pH buffering with climate-change induced ocean acidification, and organic carbon bioavailability in melting permafrost. In this study, we advance the atomic level understanding of calcite dissolution mechanisms to improve our ability to predict this complex process. We performed high pressure and temperature (1300 psi and 50 °C) batch experiments to measure transient dissolution of freshly cleaved calcite under H2O, H+, and H2CO3-dominated conditions, without and with an inhibitory anionic surfactant present. Before and after dissolution experiments, we measured dissolution etch-pit geometries using laser profilometry, and we used density functional theory to investigate relative adsorption energies of competing species that affect dissolution. Our results support the hypothesis that calcite dissolution is controlled by the ability of H2O to preferentially adsorb to surface Ca atoms over competing species, even when dissolution is dominated by H+ or H2CO3. More importantly, we identify for the first time that adsorbed H+ enhances the role of water by weakening surface Ca-O bonds. We also identify that H2CO3 undergoes dissociative adsorption resulting in adsorbed HCO3- and H+. Adsorbed HCO3- that competes with H2O for Ca acute edge sites inhibits dissolution, while adsorbed H+ at the neighboring surface of CO3 enhances dissolution. The net effect of the dissociative adsorption of H2CO3 is enhanced dissolution. These results will impact future efforts to more accurately model the impact of solutes in complex water matrices on carbonate mineral dissolution.

Ocean acidification in the tropical Indian Ocean over the past 37 years: Insights from [formula omitted]11B and B/Ca records in a Maldives coral

Boron isotopes (δ11B) in coral skeletons of Porites have been widely applied to reconstruct past seawater pH (pHSW) on decadal to centennial timescales. However, due to biological regulation within corals, an additional transfer function is required to estimate ambient seawater chemistry during the skeleton growth under the calcification site fluid pH. Temperature may also interfere with coral calcification fluid pH (pHCF) due to changes in kinetics of coral aragonite precipitation, or buffering capacity in coral calcification fluid. To decipher how coral Porites adjusts pHCF in response to pHSW from complex environmental controls, long-term records from sites with least fluctuations in environmental conditions other than pHSW are essential. Here we present a 37-year record of coral δ11B and B/Ca ratios derived from a coral core collected from southern Maldives, the tropical Indian Ocean. Our results show no clear seasonality in the coral δ11B and B/Ca ratios between monsoons, but a long-term decline in coral pHCF is evident across the entire record. When applying different existing transfer functions, we also observe discrepancies among the calculated pHCF values, model results and short-term instrumental data. Calculated calcification fluid dissolved inorganic carbon concentration ([DIC]CF) values are relatively low compared to literature, suggesting that coral calcification fluid carbonate chemistry may be under different levels of control, even within the same coral taxa. Thus, coral records from a wider geographic range are required to better quantify coral response to ocean acidification, and our results can serve as a baseline for future comparisons.

Interactive effects of ocean acidification and nitrate on Ulva lactuca

Interactive effects of ocean acidification and nitrate on Ulva lactuca

Evaluating the time to detect biological effects of ocean acidification and warming: an example using simulations of purple sea urchin settlement

Ocean acidification (OA) and ocean warming driven by climate change are important stressors for marine species and systems, but documenting and detecting their long-term impacts on biological responses outside of laboratory settings are challenging due to natural variability caused by complex processes and interactions. We used settlement of purple sea urchins Strongylocentrotus purpuratus in the Southern California Bight (USA) over 6 yr as an example data set to parameterize a simulation model for exploring the time needed to detect environmental effects on a biological response. A generalized linear model was used to describe an index of urchin settlement as functions of pH, sea surface temperature (SST), sea surface salinity (SSS), and spatio-temporal factors, demonstrating that settlement was negatively associated with pH (i.e. lower settlement at higher pH) and positively associated with SST and SSS. Monte Carlo simulations were developed from this base model under a variety of alternative scenarios to estimate the time to detect: (1) annual trends in pH and SST time series, (2) pH and SST effects on urchin settlement, and (3) annual trends in urchin settlement. Time to detect pH and SST effects was predominantly influenced by the underlying strength of the relationships and the model uncertainty. Time to detect annual trends in settlement was more sensitive to the severity of long-term OA and warming trends, which had cumulative (at times opposing) effects. This study highlights the variable time scales (2-60+ yr) that may be necessary to detect biological responses to OA and ocean warming and the sensitivity to different assumptions of the study system.

Present Scenario of Ocean Warming (OW) and Ocean Acidification (OA) in the Coastal and Marine Waters of the Bay of Bengal, Bangladesh and Implications of OW and OA on Fisheries and Seafood of Bangladesh: A First Regional Review Study

Bangladesh is one of the most vulnerable countries in the world to climate change. However, data relevant to ocean warming (OW) and ocean acidification (OA) are not readily available. This is the first study to review the available data relating to OW and OA covering the three parts (eastern, central and western parts) of the coastal marine waters (CMWs) of the Bay of Bengal (BoB), Bangladesh. The review compared the data collected from the three parts of the BoB, Bangladesh with the data and information of previous research carried out within the Indian subcontinent of the BoB (2000-2023). The present research provides an overview of water quality data relevant to OW and OA and the correlation among different water quality parameters. Our research found that the sea surface temperature is increasing and pH levels are decreasing in the BoB, Bangladesh. The current pH in BoB, Bangladesh is still alkaline, with an overall mean pH of 7.58 compared with the global ocean pH of 8.1. DO (overall mean: 6.09 mg/L), Ωarg (overall mean: 2.27) and Ωcal (overall mean: 3.59) levels were found to be within the safe thresholds for marine biota (fish, crustaceans, mussels, oysters, corals and echinoderms). Conversely, nitrate levels (mean: 2.29 mg/L) were found to be high, the concentration of which may enhance nitrogen pollution, algal blooms and hypoxia in the BoB, Bangladesh. The implications of OW and OA on Bangladesh’s fisheries and seafood have been briefly discussed.

Impact of Ocean Acidification on Plankton – A Short Review

“Ocean acidification” (OA) is a result of global warming, which describes a long-term drop in the pH of the ocean, mostly due to the ocean’s absorption of carbon dioxide (CO2) from the atmosphere. Plankton, a diverse collection of tiny organisms, are decisive in supporting marine and freshwater food webs living at and beneath the surface of lakes, rivers, ponds, and oceans across the planet. Recently this vital community has been severely affected due to ocean acidification, which has forced it to either die or they are migrating significantly as OA intensifies. This review provides a concise overview of the impacts of ocean acidification (OA) and other environmental factors on plankton communities thereby highlighting the necessity of conducting comprehensive assessments to provide insights into the impacts of climate change on marine ecosystems.

Predictable patterns within the kelp forest can indirectly create temporary refugia from ocean acidification

Kelps are recognized for providing many ecosystem services in coastal areas and considered in ocean acidification (OA) mitigation. However, assessing OA modification requires an understanding of the multiple parameters involved in carbonate chemistry, especially in highly dynamic systems. We studied the effects of sugar kelp (Saccharina latissima) on an experimental farm at the north end of Hood Canal, Washington—a low retentive coastal system. In this field mesocosm study, two oyster species (Magallana gigas, Ostrea lurida) were exposed at locations in the mid, edge, and outside the kelp array. The Hood Head Sugar Kelp Farm Model outputs were used to identify dominating factors in spatial and temporal kelp dynamics, while wavelet spectrum analyses helped in understanding predictability patterns. This was linked to the measured biological responses (dissolution, growth, isotopes) of the exposed organisms. Positioned in an area of high (sub)-diel tidal fluxes with low retention potential, there were no measurable alterations of the seawater pH at the study site, demonstrating that the kelp array could not induce a direct mitigating effect against OA. However, beneficial responses in calcifiers were still observed, which are linked to two causes: increased pH predictability and improved provisioning through kelp-derived particulate organic resource utilization and as such, kelp improved habitat suitability and indirectly created refugia against OA. This study can serve as an analogue for many coastal bay habitats where prevailing physical forcing drives chemical changes. Future macrophyte studies that investigate OA mitigating effects should focus also on the importance of predictability patterns, which can additionally improve the conditions for marine calcifiers and ecosystem services vulnerable to or compromised by OA, including aquaculture sustainability.

Diverse inorganic carbon uptake strategies in Antarctic seaweeds: Revealing species-specific responses and implications for Ocean Acidification

Seaweeds are important components of coastal benthic ecosystems along the Western Antarctic Peninsula (WAP), providing refuge, food, and habitat for numerous associated species. Despite their crucial role, the WAP is among the regions most affected by global climate change, potentially impacting the ecology and physiology of seaweeds. Elevated atmospheric CO2 concentrations have led to increased dissolved inorganic carbon (Ci) with consequent declines in oceanic pH and alterations in seawater carbonate chemistry, known as Ocean Acidification (OA). Seaweeds possess diverse strategies for Ci uptake, including CO2 concentrating mechanisms (CCMs), which may distinctly respond to changes in Ci concentrations. Conversely, some seaweeds do not operate CCMs (non-CCM species) and rely solely on CO2. Nevertheless, our understanding of the status and functionality of Ci uptake strategies in Antarctic seaweeds remains limited. Here, we investigated the Ci uptake strategies of seaweeds along a depth gradient in the WAP. Carbon isotope signatures (δ13C) and pH drift assays were used as indicators of the presence or absence of CCMs. Our results reveal variability in CCM occurrence among algal phyla and depths ranging from 0 to 20 m. However, this response was species specific. Among red seaweeds, the majority relied solely on CO2 as an exogenous Ci source, with a high percentage of non-CCM species. Green seaweeds exhibited depth-dependent variations in CCM status, with the proportion of non-CCM species increasing at greater depths. Conversely, brown seaweeds exhibited a higher prevalence of CCM species, even in deep waters, indicating the use of CO2 and HCO3−. Our results are similar to those observed in temperate and tropical regions, indicating that the potential impacts of OA on Antarctic seaweeds will be species specific. Additionally, OA may potentially increase the abundance of non-CCM species relative to those with CCMs.

ANALYZING THE PROPERTIES OF A COMPOSITE OF PCL-GRAPHITE BY THE INJECTION MOLDING

Coral reefs are vulnerable to several natural phenomena such as ocean warming, acidification, coral diseases, and plastic pollution. In order to tackle these problems, scientists are now working on the development of biocomposites utilizing biodegradable polymers such as polycaprolactone (PCL). Graphite can be used in conjunction with PCL to enhance its characteristics. The work is centered around conducting water absorption experiments on a composite material consisting of PCL and graphite. The investigation employs PCL granular and graphite powdered materials. The materials undergo heating, crushing, and weighing processes to ascertain weight ratios. Next, the mixture is shaped into specimens. The product's shape and distribution of chemical constituents are analyzed using water absorption, hydrophobicity, FTIR, and SEM testing. The findings indicate that the water absorption diminishes as the concentration of graphite powder increases. An alloy containing 10% graphite had the highest water absorption rate. The hydrophobicity test assesses the ability of a specimen's surface to repel water by introducing NaCl droplets and observing droplet production. The contact angle value exhibits a direct correlation with the increase in graphite content. The FTIR study indicates that there are no changes in the functional groups, resulting in a limited connection between the PCL matrix and the graphite filler. The temperature during the injection molding process affects the microstructure of the polymer. Lower temperatures lead to reduced crystallization, whereas higher temperatures result in denser molecular groupings. Graphite is a highly suitable choice for use as a filler in a PCL matrix because of its layered structure, large surface area, and excellent capacity to effectively fill voids within the matrix.

Preliminary investigation on the potential involvement of an ABC-like gene in Halomicronema metazoicum (Cyanobacteria) tolerance to low seawater pH in an ocean acidification scenario

Decreasing ocean surface pH, called ocean acidification (OA), is among the major risks for marine ecosystems due to human-driven atmospheric pCO2 increase. Understanding the molecular mechanisms of adaptation enabling marine species to tolerate a lowered seawater pH could support predictions of consequences of future OA scenarios for marine life. This study examined whether the ATP-binding cassette (ABC)-like gene slr2019 confers tolerance to the marine cyanobacterium Halomicronema metazoicum to low seawater pH conditions (7.7, 7.2, 6.5) in short- and long-term exposures (7 and 30 d). Photosynthetic pigment content indicated that the species can tolerate all three lowered-pH conditions. At day 7, slr2019 was up-regulated at pH 7.7 while no changes were observed at lower pH. After 30-d exposure, a significant decrease in slr2019 transcript levels was observed in all low-pH treatments. These first results indicate an effect of low pH on the examined transporter expression in H. metazoicum.

Ocean Acidification: Effects on Sponges

Approximately 30% of the carbon dioxide (CO2) released into the atmosphere has been absorbed by the world’s oceans. As CO2 emissions increase due to human activities so does the amount of CO2 absorbed by the oceans. Carbon dioxide lowers the pH of the ocean system, causing ocean acidification (OA). The effects of OA on economically and ecologically important aquatic species is a subject of interest. Sponges are important reef-associated species that provide shelter for fish and crustaceans in reef habitats and can also structure ecosystems through bioerosion, water filtration, and colonization of coral reef areas. This publication considers the effects of OA on marine sponges, with a focus on Florida’s coral reef.

Carbon export from submarine groundwater discharge in a semi-enclosed bay: Impact for the buffering capacity against coastal ocean acidification

Submarine groundwater discharge (SGD) serves as an important pathway for the transport of dissolved carbon from land to ocean, significantly affecting the coastal biogeochemical cycles. However, the impact of SGD-derived dissolved carbon on the coastal carbon budget remains poorly understood. This study first quantified SGD and associated dissolved organic carbon (DOC), dissolved inorganic carbon (DIC) and total alkalinity (TA) fluxes in Daya Bay using mass balance models based on radium isotopes (223Ra, 224Ra, 226Ra and 228Ra). We then constructed carbon mass balance models to evaluate the impact of SGD-derived carbon on the buffering capacity against coastal ocean acidification. The estimated SGD fluxes ranged from 0.80 × 107 to 2.64 × 107 m3d−1. The DIC, DOC and TA fluxes from SGD were 17.90–36.44 mmol m−2d−1, 0.93–2.13 mmol m−2d−1, and 21.19–28.47 mmol m−2d−1, respectively. Based on carbon mass balances, the DIC flux from SGD was 19–39 times the riverine input, accounting for 27.16 % ∼ 37.64 % of the total carbon source. These results suggest that SGD is a major contributor to DIC, significantly affecting the coastal carbon budget. Furthermore, the average TA:DIC ratio of groundwater discharging into Daya Bay was approximately 1.13. High TA exports enhance the buffering capacity of the coastal ocean and contribute bicarbonate to the ocean, playing a significant role in the ocean carbon sequestration process. This study demonstrates the importance of SGD-derived dissolved carbon in the assessment of coastal carbon budgets.

Antioxidant and Metabolic Response to Acute Acidification Stress of Juvenile Yellowfin Tuna (Thunnus albacares)

This study aimed to explore the impact of acute acidification on the antioxidant, metabolic performance, and liver histology of juvenile yellowfin tuna. The experiment subjected juvenile yellowfin tuna to a pH gradient environment of 8.1, 7.6, 7.1, and 6.6 for 48 h. The findings indicate that a seawater pH of 7.1 significantly impacts the antioxidant and metabolic systems of the juvenile yellowfin tuna in comparison to the control group. At pH 7.1, there were observed increases in glutathione reductase (GR), total antioxidant capacity (T-AOC), lactate dehydrogenase (LDH), hexokinase (HK), pyruvate kinase (PK), sodium-potassium ATPase (Na+K+-ATP), and calcium-magnesium ATPase (Ca2+Mg2+-ATP). Conversely, low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TGs) were not significantly different across the treatment groups. However, an increase in transaminases at pH 7.1 suggested potential liver damage, which was further supported by observed structural liver tissue degeneration and hepatocyte vacuolation. In conclusion, under conditions of acute acidification stress, there is a decrease in antioxidant capacity and a suppression of metabolic levels in juvenile yellowfin tuna, leading to oxidative damage. This study lays the foundation for an in-depth understanding of the response mechanisms of juvenile yellowfin tuna in response to seawater acidification as well as healthy tuna farming in the broader context of seawater acidification.

Ein experimentelles Mystery und ein Modellexperiment zur Ozeanversauerung – umgesetzt im Schülerlabor KOALa

Ein experimentelles Mystery und ein Modellexperiment zur Ozeanversauerung – umgesetzt im Schülerlabor KOALa

Physiological responses of Atlantic cod to climate change indicate that coastal ecotypes may be better adapted to tolerate ocean stressors

Healthy ecosystems and species have some degree of resilience to changing conditions, however as the frequency and severity of environmental changes increase, resilience may be diminished or lost. In Sweden, one example of a species with reduced resilience is the Atlantic cod (Gadus morhua). This species has been subjected to overfishing, and with additional pressures such as habitat degradation and changing environmental conditions there has been little to no recovery, despite more than a decade of management actions. Given the historical ecological, economical, and cultural significance of cod, it is important to understand how Atlantic cod respond to global climate change to recover and sustainably manage this species in the future. A multi-stressor experiment was conducted to evaluate physiological responses of juvenile cod exposed to warming, ocean acidification, and freshening, changes expected to occur in their nursery habitat. The response to single drivers showed variable effects related to fish biometrics and increased levels of oxidative stress dependent parameters. Importantly, two separate responses were seen within a single treatment for the multi-stressor and freshening groups. These within-treatment differences were correlated to genotype, with the offshore ecotype having a heightened stress response compared to the coastal ecotype, which may be better adapted to tolerate future changes. These results demonstrate that, while Atlantic cod have some tolerance for future changes, ecotypes respond differently, and cumulative effects of multiple stressors may lead to deleterious effects for this important species.