Rapid Changes In Salinity Research Articles

Stress responses in an Arctic microalga (Pelagophyceae) following sudden salinity change revealed by gene expression analysis

Marine microbes that have for eons been adapted to stable salinity regimes are confronted with sudden decreases in salinity in the Arctic Ocean. The episodic freshening is increasing due to climate change with melting multi-year sea-ice and glaciers, greater inflows from rivers, and increased precipitation. To investigate algal responses to lowered salinity, we analyzed the responses and acclimatation over 24 h in a non-model Arctic marine alga (pelagophyte CCMP2097) following transfer to realistic lower salinities. Using RNA-seq transcriptomics, here we show rapid differentially expressed genes related to stress oxidative responses, proteins involved in the photosystem and circadian clock, and those affecting lipids and inorganic ions. After 24 h the pelagophyte adjusted to the lower salinity seen in the overexpression of genes associated with freezing resistance, cold adaptation, and salt tolerance. Overall, a suite of ancient widespread pathways is recruited enabling the species to adjust to the stress of rapid salinity change.

How does rapid burial work? New insights from experiments with echinoderms

AbstractThis research explores the significance of rapid burial in preserving fossils, with a particular focus on free‐living echinoderms. Experiments were based on ophiuroids to simulate burial under different turbiditic flows. The results showed that a bed thickness of around 10 cm is a limit for the preservation of whole skeletons in most cases. The type of sediment can affect the integrity of the buried skeletons, with sand deposition resulting in higher rates of autotomy. However, mud deposition did not show any numbing effect, as previously believed for echinoderms. In contrast, freshwater‐rich sediments can play a critical role, paralysing specimens and preventing escape postures through rapid changes in salinity. From this, the study highlights the importance of extrabasinal turbidites, generated outside the marine basin, in the fossilization of marine invertebrates. Such sediments are rich in fresh water and can be more efficient burial traps compared to other intrabasinal deposits generated by storm waves or submarine landslides.

Seasonal and spatial dynamics of mesozooplankton community in a subtropical embayment

Mesozooplankton abundance and community composition are influenced by hydrography and biological interactions. In subtropical systems influenced by seasonal monsoons, seasonal cycle of plankton communities could be disrupted and restructured by short but intense weather events. Our survey of a shallow subtropical embayment to the northern part of the South China Sea demonstrated temporal variations in zooplankton biomass and composition between monsoon periods: not only were the wet (summer monsoon) and dry (winter monsoon) periods distinctive from each other, but also the transition phase between the two. The meroplankton communities were distinct between the monsoon periods with fish, decapods and echinoderm peaked during the wet season and cirripedia bloomed in dry season. This pattern can be attributed to both changes in growth conditions and influx of individuals through monsoon-driven water currents. The community shift during the transitional phase, defined by the rapid changes in salinity and temperature, corresponded to the reported reproductive cycles of marine organisms, including commercially important fishes, crustaceans, and echinoderms. The interannual variability observed during the wet period reflected changes in rainfall between consecutive years, highlighting the importance of having a long time series with which to establish a baseline information to better manage nursery habitats like the one surveyed, particularly in light of increasing coastal development. Subtropical coastal zooplankton communities are highly dynamic with multiple pulses and interruptions driven by weather events.

Recognizing Salinity Threats in the Climate Crisis.

Climate change is causing habitat salinity to transform at unprecedented rates across the globe. While much of the research on climate change has focused on rapid shifts in temperature, far less attention has focused on the effects of changes in environmental salinity. Consequently, predictive studies on the physiological, evolutionary, and migratory responses of organisms and populations to the threats of salinity change are relatively lacking. This omission represents a major oversight, given that salinity is among the most important factors that define biogeographic boundaries in aquatic habitats. In this perspective, we briefly touch on responses of organisms and populations to rapid changes in salinity occurring on contemporary time scales. We then discuss factors that might confer resilience to certain taxa, enabling them to survive rapid salinity shifts. Next, we consider approaches for predicting how geographic distributions will shift in response to salinity change. Finally, we identify additional data that are needed to make better predictions in the future. Future studies on climate change should account for the multiple environmental factors that are rapidly changing, especially habitat salinity.

Ion Transporter Gene Families as Physiological Targets of Natural Selection During Salinity Transitions in a Copepod.

Salinity is a key factor that structures biodiversity on the planet. With anthropogenic change, such as climate change and species invasions, many populations are facing rapid and dramatic changes in salinity throughout the globe. Studies on the copepod Eurytemora affinis species complex have implicated ion transporter gene families as major loci contributing to salinity adaptation during freshwater invasions. Laboratory experiments and population genomic surveys of wild populations have revealed evolutionary shifts in genome-wide gene expression and parallel genomic signatures of natural selection during independent salinity transitions. Our results suggest that balancing selection in the native range and epistatic interactions among specific ion transporter paralogs could contribute to parallel freshwater adaptation. Overall, these studies provide unprecedented insights into evolutionary mechanisms underlying physiological adaptation during rapid salinity change.

Effect of temperature and salinity on the growth and cell size of the first cultures of Gymnodinium aureolum from the Black Sea

Abstract Algal blooms are natural phenomena that may cause human health problems, millions of dollars in losses and ecological disasters worldwide. Anthropogenic pressures like eutrophication may increase the frequency and intensity of these phenomena. The Black Sea is characterized by rapid changes in salinity and temperature in surface waters. In addition, it has suffered increasing environmental pressure from human activities. This work presents the first cultures of Gymnodinium aureolum to be isolated from the Black Sea. Morphological and phylogenetic analyses confirmed our strain as G. aureolum. The effects of temperature and salinity on growth were tested in experiments combining two temperatures and five salinities in 10 experimental treatments. This provides baseline data on the physiological adaption and acclimatization potential of the species to bloom under present and future climatic scenarios in the Black Sea. Gymnodinium aureolum grew exponentially in all experimental treatments, except for cultures at salinity 5. Growth rate increased significantly with increasing temperature reaching the maximum at 20 °C and salinity 15 (0.38 ± 0.02 d−1). This suggests an adaptation to the salinity and temperature of Black Sea waters and, together with previous records of G. aureolum in both water and sediments, supports the idea that this may be a bloom-forming population of G. aureolum.

Physiological and behavioral response of the Asian shore crab, Hemigrapsus sanguineus, to salinity: implications for estuarine distribution and invasion.

The invasive Asian shore crab, Hemigrapsus sanguineus, is ubiquitous in the rocky intertidal zone of the western North Atlantic. A likely contributor to this colonization is that H. sanguineus is able to handle a wide range of salinities, and is thus more likely to spread through a greater geographic area of estuaries. This study investigated the salinity effects on this animal by observing survival across a range of salinities, the maintenance of hemolymph osmolality under different salinities, and behavioral preference for and avoidance of salinities. H. sanguineus showed high survival across a broad range of salinities, had little change in hemolymph osmolality over a short-term salinity shock, and behaviorally distinguished between salinities when presented with a choice, under both acclimation salinities of 5 PSU or 35 PSU. Such results suggest H. sanguineus has a hardiness for the rapid changes in salinity that happen in the intertidal zone, yet is capable of physically moving to a more optimal salinity. This enhances their competitiveness as an invader, particularly surviving lower salinities that present challenges during high-precipitation events in rocky intertidal areas, and partially explains this species’ dominance in this habitat type.

Microbial Community Structure and Functional Potential Along a Hypersaline Gradient.

Salinity is one of the strongest environmental drivers of microbial evolution and community composition. Here we aimed to determine the impact of salt concentrations (2.5, 7.5, and 33.2%) on the microbial community structure of reclaimed saltern ponds near San Francisco, California, and to discover prospective enzymes with potential biotechnological applications. Community compositions were determined by 16S rRNA amplicon sequencing revealing both higher richness and evenness in the pond sediments compared to the water columns. Co-occurrence network analysis additionally uncovered the presence of microbial seed bank communities, potentially primed to respond to rapid changes in salinity. In addition, functional annotation of shotgun metagenomic DNA showed different capabilities if the microbial communities at different salinities for methanogenesis, amino acid metabolism, and carbohydrate-active enzymes. There was an overall shift with increasing salinity in the functional potential for starch degradation, and a decrease in degradation of cellulose and other oligosaccharides. Further, many carbohydrate-active enzymes identified have acidic isoelectric points that have potential biotechnological applications, including deconstruction of biofuel feedstocks under high ionic conditions. Metagenome-assembled genomes (MAGs) of individual halotolerant and halophilic microbes were binned revealing a variety of carbohydrate-degrading potential of individual pond inhabitants.

Euryhaline ecology of early tetrapods revealed by stable isotopes.

The fish-to-tetrapod transition-followed later by terrestrialization-represented a major step in vertebrate evolution that gave rise to a successful clade that today contains more than 30,000 tetrapod species. The early tetrapod Ichthyostega was discovered in 1929 in the Devonian Old Red Sandstone sediments of East Greenland (dated to approximately 365 million years ago). Since then, our understanding of the fish-to-tetrapod transition has increased considerably, owing to the discovery of additional Devonian taxa that represent early tetrapods or groups evolutionarily close to them. However, the aquatic environment of early tetrapods and the vertebrate fauna associated with them has remained elusive and highly debated. Here we use a multi-stable isotope approach (δ13C, δ18O and δ34S) to show that some Devonian vertebrates, including early tetrapods, were euryhaline and inhabited transitional aquatic environments subject to high-magnitude, rapid changes in salinity, such as estuaries or deltas. Euryhalinity may have predisposed the early tetrapod clade to be able to survive Late Devonian biotic crises and then successfully colonize terrestrial environments.

Effects of Extreme Events on Arsenic Cycling in Salt Marshes

AbstractExtreme events such as storm surges, intense precipitation, and supermoons cause anomalous and large fluctuations in water level in tidal salt marshes, which impacts the sediment biogeochemistry that dictates arsenic (As) cycling. In addition to changes in water level, which impacts soil redox potential, these extreme events may also change salinity due to freshwater inputs from precipitation or saltwater inputs due to surge. It is currently unknown how As mobility in tidal salt marshes will be impacted by extreme events, as fluctuations in salinity and redox potential may act synergistically to mobilize As. To investigate impacts of extreme events on As cycling in tidal salt marshes, we conducted a combined laboratory and field investigation. We monitored pore water and soil samples before, during, and after two extreme events: a supermoon lunar eclipse followed by a storm surge and precipitation induced by Hurricane Joaquin in fall 2015 at the St. Jones Reserve in Dover, Delaware, a representative tidal salt marsh in the Mid‐Atlantic United States. We also conducted soil incubations of marsh sediments in batch and in flow‐through experiments in which redox potential and/or salinity were manipulated. Field investigations showed that pore water As was inversely proportional to redox potential. During the extreme events, a distinct pulse of As was observed in the pore water with maximum salinity. Combined field and laboratory investigations revealed that this As pulse is likely due to rapid changes in salinity. These results have implications for As mobility in the face of extreme weather variability.

Salinity Variations of the Intermediate Oyashio Waters and Their Relation with the Lunar Nodal Cycle

New oceanographic observations in the period 1990–2015 revealed significant salinity variations in the Oyashio Current. In the last 26 years, the salinity of the upper layer decreased by 0.2 PSU. The most rapid changes in salinity and temperature have been observed in the last five years. The time series of salinity measurements is characterized by the high-amplitude fluctuations synchronized with the lunar nodal cycle (18.6 years); i.e., high salinity is observed in the period of strong tidal currents. Modulation of diurnal tidal currents with the K1 and O1 periods in the lunar nodal cycle is significant [8, 9]. The amplitude was maximal in 1988 and 2006 and minimal in 1997 and 2015. The characteristics of tidal currents in the Oyashio Current and Sea of Okhotsk are considered based on available data of drifting buoys over the Kruzenshtern and Kashevarov banks. The amplitude of salinity variations synchronized with the lunar cycle is approximately 0.1 PSU; therefore, it has made a significant contribution to the salinity decrease in recent years.

Dynamics of Gene Expression Responses for Ion Transport Proteins and Aquaporins in the Gill of a Euryhaline Pupfish during Freshwater and High-Salinity Acclimation

Pupfishes (genus Cyprinodon) evolved some of the broadest salinity tolerances of teleost fishes, with some taxa surviving in conditions from freshwater to nearly 160 ppt. In this study, we examined transcriptional dynamics of ion transporters and aquaporins in the gill of the desert Amargosa pupfish (Cyprinodon nevadensis amargosae) during rapid salinity change. Pupfish acclimated to 7.5 ppt were exposed to freshwater (0.3 ppt), seawater (35 ppt), or hypersaline (55 ppt) conditions over 4 h and sampled at these salinities over 14 d. Plasma osmolality and Cl- concentration became elevated 8 h after the start of exposure to 35 or 55 ppt but returned to baseline levels after 14 d. Osmolality recovery was paralleled by increased gill Na+/K+-ATPase activity and higher relative levels of messenger RNAs (mRNAs) encoding cystic fibrosis transmembrane conductance regulator (cftr) and Na+/K+/2Cl- cotransporter-1 (nkcc1). Transcripts encoding one Na+-HCO3- cotransporter-1 isoform (nbce1.1) also increased in the gills at higher salinities, while a second isoform (nbce1.2) increased expression in freshwater. Pupfish in freshwater also had lower osmolality and elevated gill mRNAs for Na+/H+ exchanger isoform-2a (nhe2a) and V-type H+-ATPase within 8 h, followed by increases in Na+/H+ exchanger-3 (nhe3), carbonic anhydrase 2 (ca2), and aquaporin-3 (aqp3) within 1 d. Gill mRNAs for Na+/Cl- cotransporter-2 (ncc2) also were elevated 14 d after exposure to 0.3 ppt. These results offer insights into how coordinated transcriptional responses for ion transporters in the gill facilitate reestablishment of osmotic homeostasis after changes in environmental salinity and provide evidence that the teleost gill expresses two Na+-HCO3- cotransporter-1 isoforms with different roles in freshwater and seawater acclimation.

Rapid salinity changes affect the survival and physiology of a penaeid prawn: Implications of flood events on recruitment to the fishery

AbstractEstuaries act as nurseries for many penaeid prawns, but these habitats are highly susceptible to salinity decline through flooding. The rate of salinity decline and duration of exposure to non‐optimal salinity may affect survival and subsequent recruitment of prawns to the fishery. This study aimed to determine the effect of salinity fluctuations observed in local estuaries during flood events using a novel dilution approach. Mortality of juvenile Melicertus plebejus (Hess) was assessed after 24 hr exposure to 24 rates of salinity decline ranging from 0.01% to 20% per hr. After the salinity decline, prawns were held at the final salinities for five days before again assessing mortality as well as aerobic metabolic rate and prawn water content. Salinity decline from 36 to ~0.8 led to 50% mortality, but continued exposure to low salinity for five days increased mortality at this salinity to 99% and shifted the 50% mortality point to salinity ~5. Aerobic metabolic rate and water content data suggested the cause of mortality due to exposure to salinities < 5 was osmoregulatory failure. Rapid salinity declines over 24 hr and sustained low salinity due to flooding could compromise the survival of juvenile prawns, potentially reducing recruitment to the fishery.

Salinity effects on osmoregulation and gill morphology in juvenile Persian sturgeon (Acipenser persicus).

The effect of abrupt and 5-day gradual salinity transfers from freshwater (FW) to 11‰ Caspian Sea brackish water (BW) was investigated in juvenile Persian sturgeon Acipenser persicus with three different weight groups: 1-2g (1.62±0.27g), 2-3g (2.55±0.41g) and 3-5g (4.28±0.76g). Mortality rates, blood osmotic pressure, gill morphology and branchial Na+, K+-ATPase (NKA) activity were measured 4 and 10days after abrupt transfer and 9 and 15days after the initial gradual transfer (i.e. 4 and 10days after reaching Caspian Sea salinity). Fish under 3g could not survive increased salinity, and the blood osmotic pressure of the remaining surviving fish increased and remained elevated. However, heavier fish were able to survive and successfully acclimate, even to rapid salinity change with osmotic pressure reduced to Caspian Sea osmolality levels. At the gill level, the developmental increase in chloride cell volume and a higher NKA content most probably allow juveniles weighing more than 2g to sharply increase NKA activity if the fish are transferred to BW. The rapid chloride cell proliferation occurring with increased salinity should strengthen this acclimation response. Therefore, a drastic physiological change occurs when fish weigh more than 2g that allows migration to higher salinities. The triggering signal on chloride cells must be further investigated in order to optimize this functional step.

Adsorption and desorption of dissolved organic matter by carbon nanotubes: Effects of solution chemistry

Increasing use of carbon nanotubes (CNTs) has led to their introduction into the environment where they can interact with dissolved organic matter (DOM). This study focuses on solution chemistry effects on DOM adsorption/desorption processes by single-walled CNTs (SWCNTs). Our data show that DOM adsorption is controlled by the attachment of DOM molecules to the SWCNTs, and that the initial adsorption rate is dependent on solution parameters. Adsorbed amount of DOM at high ionic strength was limited, possibly due to alterations in SWCNT bundling. Desorption of DOM performed at low pH resulted in additional DOM adsorption, whereas at high pH, adsorbed DOM amount decreased. The extent of desorption conducted at increased ionic strength was dependent on pre-adsorbed DOM concentration: low DOM loading stimulated additional adsorption of DOM, whereas high DOM loading facilitated release of adsorbed DOM. Elevated ionic strength and increased adsorbed amount of DOM reduced the oxidation temperature of the SWCNTs, suggesting that changes in the assembly of the SWCNTs had occurred. Moreover, DOM-coated SWCNTs at increased ionic strength provided fewer sites for atrazine adsorption. This study enhances our understanding of DOM–SWCNT interactions in aqueous systems influenced by rapid changes in salinity, and facilitates potential use of SWCNTs in water-purification technologies.

The interactive influence of temperature and salinity on larval and juvenile growth in the gastropod Crepidula fornicata (L.)

Sea surface temperatures have been rising and are predicted to continue rising in coming years because of global warming. In addition, salinity has been decreasing in high latitudes and is expected to continue decreasing due to altered precipitation patterns and glacial melting caused by climate change. Many marine organisms that are adapted to the present conditions may be drastically affected by these oceanic changes. Early life stages (larvae and juveniles) should be especially susceptible, since they do not yet have the fully developed morphological defenses of adults. This study investigated the effects of reduced salinity (20 compared to a control of 30) and altered temperature (15, 20, 25, and 29°C) on the growth, percent inorganic content (representing shell calcification), and feeding rates of larvae and juveniles of the widespread coastal snail Crepidula fornicata. Both larval and juvenile growth rates were significantly depressed at low salinity and lower temperatures. In addition, the salinity that snails were exposed to as larvae significantly impacted their juvenile growth rates in 4 out of 6 treatments, an example of latent effects. The magnitude and direction of this effect were strongly impacted by temperature and parentage. Juvenile feeding rates were significantly depressed following a rapid change in salinity but then gradually recovered to near initial levels over 3h. There was little difference in the percent inorganic content of juveniles but for larvae that had been reared at 20°C, percent inorganic content was 27% lower for those reared at a salinity of 20 compared with those reared at 30. In conclusion, the early life stages of C. fornicata may experience more favorable conditions in a warmer future: growth rates will increase, probably making larvae and juveniles less vulnerable to size-specific predation. Conversely, in regions where salinity is decreasing, C. fornicata larvae and juveniles will likely grow more slowly, thereby increasing predation risk by forcing them to spend more time at more vulnerable smaller sizes. Thus, the future of C. fornicata and their potential to continue invading new habitats will depend greatly on the specific salinity and temperature conditions they will be exposed to throughout larval and juvenile development.

Stranded: The Conquest of Fresh Water by Marine Ostracods

The earliest freshwater colonisation by marine ostracods probably took place in the early Carboniferous. The first low-salinity habitats invaded by ostracods were likely ephemeral ponds near the shoreline, or fluvial, deltaic settings influenced by marine transgression events. The dominant factor in such environments is rapid change in salinity resulting from fluctuations in sea level, evaporation and precipitation, so the first freshwater colonisers are likely to have been tolerant euryhaline species. The most obvious adaptation to such environments is tolerance to low-salinity conditions. Modern studies report that ostracods possess efficient osmoregulatory mechanisms and are characterised by wide tolerance to different salinity regimes. They also exhibit other characteristics such as mixing reproductive mode, resting and/or desiccation-resistant eggs, and brood care which may facilitate colonisation of different regimes. Ostracods possess a calcified carapace containing high concentrations of calcium carbonate but shell formation may be less effective in poorly mineralised fresh waters. However, the mineral content of early Carboniferous coastal ponds was most probably sufficient to allow the development of calcified carapaces by the first freshwater species.

Semidiurnal Dynamics of Phytoplankton Size Structure and Taxonomic Composition in a Macrotidal Temperate Estuary

The semidiurnal dynamics of phytoplankton in a temperate macrotidal estuary were explored by monitoring phytoplankton size structure and taxonomic composition at a fixed station on a seasonal basis. Phytoplankton chlorophyll a (chl a, a proxy for biomass) varied out of phase with the tidal height in February, May, and November, but varied in phase with the tidal height in July. The in-phase pattern in July was observed because the horizontal gradient of chl a differed from other seasons. The horizontal chl a gradient was affected by salinity decrease resulting from the regulated freshwater discharge that occurred 1 day before the diel monitoring in July. This suggests that phytoplankton chl a varies with the rapid change in salinity resulting from anthropogenic freshwater inputs from sea dikes, in addition to varying with tidal currents in the estuary. This season-dependent pattern of response to tidal forcing has not been observed in other temperate estuaries. The relationship with tidal height was enhanced as cell size increased from pico- to micro-size, as the horizontal chl a gradients of larger cells were more evident than those of pico-sized cells. The abundance of diatoms, a dominant group throughout all seasons, fluctuated with tidal height, as did the large cells, whereas the dominant diatom species shifted quickly, and tidal effects on phytoplankton species were not evident. The intra-tidal variations in the phytoplankton community were substantial, but were explained mainly by tidal currents (except at the species level) and as the effect of regulated freshwater input, even when freshwater was no longer being discharged. This suggests that tidal phase and salinity are important parameters to consider in determining long-term trends and seasonal variations in the phytoplankton communities of macrotidal estuaries altered by engineered structures such as sea dikes.

Seagrass (Ruppia maritima L.) Life History Transitions in Response to Salinity Dynamics Along the Everglades-Florida Bay Ecotone

Coastal estuaries receiving low and fluctuating freshwater flows are creating more variable salinity environments for submerged aquatic vegetation (SAV), including seagrasses. Some SAV species, such as Ruppia maritima L. (wigeongrass), are adapted to variable salinity, but rapid salinity changes can limit population persistence. For example, R. maritima historically dominated at the Everglades-Florida Bay ecotone under greater freshwater flows, but has a more limited distribution in recent decades with greater salinity variability. While R. maritima is an indicator species for Everglades restoration, little is known about how ecotone salinity patterns drive its current limited distribution in southern Everglades estuaries. Seed production is important for population maintenance in this disturbance-tolerant species. Thus, we examined R. maritima life history transitions, including seed germination, seedling and adult survival, and sexual reproduction under site-specific salinity variability across the Everglades ecotone. Seedlings were most susceptible to fluctuating salinity with only 13 % survival at the lower more marine ecotone site under conditions of relatively large-amplitude fluctuations. Adult survival also decreased from upper (93 %) to lower (25 %) sites, resulting in a significant decline in per capita clonal reproduction rates. The markedly low survival rate at the lower ecotone was associated with rapid salinity fluctuations (2.5–20 psu) with short periodicities (<24 h). In addition, no sexual reproduction occurred at any of our ecotone sites, indicating that seed production may be limiting. Thus, hydrologic restoration targets should consider optimization of salinity levels and dynamics that promote SAV early life stage survival and sexual reproduction to restore critical coastal habitats in the Everglades and other highly dynamic estuarine systems.

A Spatio-Temporal Understanding of Growth Regulation during the Salt Stress Response in Arabidopsis

Plant environmental responses involve dynamic changes in growth and signaling, yet little is understood as to how progress through these events is regulated. Here, we explored the phenotypic and transcriptional events involved in the acclimation of the Arabidopsis thaliana seedling root to a rapid change in salinity. Using live-imaging analysis, we show that growth is dynamically regulated with a period of quiescence followed by recovery then homeostasis. Through the use of a new high-resolution spatio-temporal transcriptional map, we identify the key hormone signaling pathways that regulate specific transcriptional programs, predict their spatial domain of action, and link the activity of these pathways to the regulation of specific phases of growth. We use tissue-specific approaches to suppress the abscisic acid (ABA) signaling pathway and demonstrate that ABA likely acts in select tissue layers to regulate spatially localized transcriptional programs and promote growth recovery. Finally, we show that salt also regulates many tissue-specific and time point-specific transcriptional responses that are expected to modify water transport, Casparian strip formation, and protein translation. Together, our data reveal a sophisticated assortment of regulatory programs acting together to coordinate spatially patterned biological changes involved in the immediate and long-term response to a stressful shift in environment.