Good News — Bad News: Combined Ocean Change Drivers Decrease Survival but Have No Negative Impact on Nutritional Value and Organoleptic Quality of the Northern Shrimp

Nutritional and organoleptic qualities (taste, smell, texture, appearance) are key characteristics of seafood when it comes to defining consumer choices. These qualities, which are determined by the biochemical properties of the seafood, can be altered by environmental conditions, such as those imposed by ongoing global ocean change. However, these effects have rarely been studied despite their potential important economic and dietary implications: many human communities depend upon seafood as a primary source of nutrition and/or income from the associated seafood industry. The Northern shrimp, Pandalus borealis, makes the 3rd most valuable fishery in Eastern Canada, and figures among the most important fisheries in the North-Eastern Atlantic. This study aimed to determine the impact of combined ocean warming, acidification and hypoxia on (a) muscle mineral content as proxy for nutritional quality, and (b) the taste, smell, texture, and appearance as proxies for organoleptic quality of this commercially important species. These proxies were determined after an exposure of 30 days under laboratory conditions to different ocean global change scenarios of temperature (2, 6, and 10°C), pH (7.75 and 7.4) and oxygen (100 and 35% relative to air saturation), in isolation and in combination. Shrimp survival was significantly lower (68%) for shrimp exposed to warming and low pH, and even lower (37%) when hypoxia was superimposed, compared to an average survival of 88% for all other treatments. Mineral contents were globally higher in shrimp exposed to the highest temperature, while organoleptic attributes were comparable across all scenarios tested. Thus, while we do not expect nutritional value and organoleptic quality of shrimp, broadly speaking, to be altered by global changes even in areas where conditions will correspond to our warmest (10°C) and lowest pH (7.4) scenarios, the lower survival rate we report could negatively impact the viability of shrimp populations and consequently the shrimp industry. This may be particularly true for areas that are currently becoming or are expected to become hypoxic. -- Keywords : Ocean warming ; Ocean acidification ; Hypoxia ; Sensory quality ; Mortality ; Seafood

COLD CASE INVESTIGATIONS WITHIN FAIRFAX COUNTY: TURNING THE LIABILITY OF TIME INTO AN ASSET

No department or individual involved in the investigation of homicides is ever going to have a 100% closure rate. Therefore, many departments will be faced with a situation where another homicide happens before they are finished handling the previous one. How does one manage these open cases; how often are they reviewed; and who is responsible once the assigned detective is either transferred or leaves the unit or department? Someone has to be able to answer questions from the family, media and anyone else who might inquire about the case. Based on the number of unsolved homicide cases within Fairfax County, the concept of a “Cold Case Squad” was explored. During January 1995, the Fairfax County Police Department implemented a Cold Case Squad consisting of one supervisor, three veteran detectives, two auxiliary police officers and one cadet. The Cold Case detectives inherited approximately 75 unsolved homicides which occurred in Fairfax County, Virginia, from 1964 through December 31, 1994. More than half of the unsolved homicides (42) have occurred in the past nine years. The hypothesis for this thesis was: The formulation of a Cold Case Squad would measurably reduce the number of unresolved homicides within Fairfax County. The primary evaluation factor for the thesis was the Cold Case Squad’s “close-ability” rate. The thesis identified and evaluated nine solvability factors utilized by the Cold Case Squad Supervisor. The solvability factors are considered when prioritizing case investigation, assigning personnel to an investigation and suspending investigate efforts. One of the goals for utilizing solvability factors is to develop a clear profile of cases with the most potential for close-ability. The study population for this thesis is the 42 unsolved homicides which have occurred in Fairfax County, Virginia, between January 1, 1986, and December 31, 1994. Solvability factor work sheets were completed and computated for the study population. The hypothesis has been proven as there is a measurable reduction in the number of unsolved homicides. From the study population, two cases have been closed by arrest, one case closed by exceptional means and one case is pending approval from the Commonwealth Attorney’s Office to obtain arrest warrants. These four cases represent a 9.5% reduction of unsolved cases within the study population. A copy of this thesis was given to the Cold Case Squad Supervisor for review and application. It is hoped the research from this thesis will be applied to the Cold Case Squad so it will become more effective and continue to turn the liability of time into an asset

The lack of genetic variation underlying thermal transcriptomic plasticity suggests limited adaptability of the Northern shrimp, Pandalus borealis

Introduction: Genetic variation underlies the populations’ potential to adapt to and persist in a changing environment, while phenotypic plasticity can play a key role in buffering the negative impacts of such change at the individual level. Methods: We investigated the role of genetic variation in the thermal response of the northern shrimp Pandalus borealis, an ectotherm species distributed in the Arctic and North Atlantic Oceans. More specifically, we estimated the proportion transcriptomic responses explained by genetic variance of female shrimp from three origins after 30 days of exposure to three temperature treatments. Results: We characterized the P. borealis transcriptome (170,377 transcripts, of which 27.48% were functionally annotated) and then detected a total of 1,607 and 907 differentially expressed transcripts between temperatures and origins, respectively. Shrimp from different origins displayed high but similar level of transcriptomic plasticity in response to elevated temperatures. Differences in transcript expression among origins were not correlated to population genetic differentiation or diversity but to environmental conditions at origin during sampling. Discussion: The lack of genetic variation explaining thermal plasticity suggests limited adaptability in this species’ response to future environmental changes. These results together with higher mortality observed at the highest temperature indicate that the thermal niche of P. borealis will likely be restricted to higher latitudes in the future. This prediction concurs with current decreases in abundance observed at the southern edge of this species geographical distribution, as it is for other cold-adapted crustaceans. Keywords : phenotypic plasticity ; climate change ; ocean warming ; crustacean ; decapod ; fisheries ; RNA-seq

Ocean acidification causes fundamental changes in the cellular metabolism of the Arctic copepod Calanus glacialis as detected by metabolomic analysis

Using a targeted metabolomic approach we investigated the effects of low seawater pH on energy metabolism in two late copepodite stages (CIV and CV) of the keystone Arctic copepod species Calanus glacialis. Exposure to decreasing seawater pH (from 8.0 to 7.0) caused increased ATP, ADP and NAD+ and decreased AMP concentrations in stage CIV, and increased ATP and phospho-L-arginine and decreased AMP concentrations in stage CV. Metabolic pathway enrichment analysis showed enrichment of the TCA cycle and a range of amino acid metabolic pathways in both stages. Concentrations of lactate, malate, fumarate and alpha-ketoglutarate (all involved in the TCA cycle) increased in stage CIV, whereas only alpha-ketoglutarate increased in stage CV. Based on the pattern of concentration changes in glucose, pyruvate, TCA cycle metabolites, and free amino acids, we hypothesise that ocean acidification will lead to a shift in energy production from carbohydrate metabolism in the glycolysis toward amino acid metabolism in the TCA cycle and oxidative phosphorylation in stage CIV. In stage CV, concentrations of most of the analysed free fatty acids increased, suggesting in particular that ocean acidification increases the metabolism of stored wax esters in this stage. Moreover, aminoacyl-tRNA biosynthesis was enriched in both stages indicating increased enzyme production to handle low pH stress

Seawater carbonate chemistry and coelomic fluid,morphometric and survival data of Paracentrotus lividus

Inter‐individual variation in phenotypic traits has long been considered as "noise" rather than meaningful phenotypic variation, with biological studies almost exclusively generating and reporting average responses for populations and species' aver‐ age responses. Here, we compare the use of an individual approach in the investigation of extracellular acid-base regulation by the purple sea urchin Paracentrotus lividus challenged with elevated pCO2 and temperature conditions, with a more traditional approach which generates and formally compares mean values. We detected a high level of inter‐individual variation in acid-base regulation parameters both within and between treatments. Comparing individual and mean values for the first (apparent) dissociation constant of the coelomic fluid for individual sea urchins resulted in substantially different (calculated) acid-base parameters, and models with stronger statistical support. While the approach using means showed that coelomic pCO2 was influenced by seawater pCO2 and temperature combined, the individual approach indicated that it was in fact seawater temperature in isolation that had a significant effect on coelomic pCO2. On the other hand, coelomic [HCO3−] appeared to be primarily affected by seawater pCO2, and less by seawater temperature, irrespective of the approach adopted. As a consequence, we suggest that individual variation in physiological traits needs to be considered, and where appropriate taken into ac‐ count, in global change biology studies. It could be argued that an approach reliant on mean values is a "procedural error." It produces an artefact, that is, a population's mean phenotype. While this may allow us to conduct relatively simple statistical analyses, it will not in all cases reflect, or take into account, the degree of (physiological) diversity present in natural populations

Metabolomics reprogramming of the northern shrimp exposed to combined ocean change drivers

The dataset contains information on the metabolomics reprogramming of the northern shrimp Pandalus borealis collected from four distinct geographic origins (i.e. St. Lawrence Estuary (SLE) 48° 35' N, 68° 35' W, May 2018 ; Eastern Scotian Shelf (ESS), 45° 23' N, 61° 04' W, February 2019 ; Esquiman Channel (EC), 50° 44' N, 57°29' W, July 2019 ; and Northeast Newfoundland Coast (NNC), 50° 18' N, 54° 16' W, November 2019) and exposed for 30 days under laboratory conditions to different ocean global change scenarios of temperature (2, 6, and 10 °C) and pH (7.75 and 7.40), in isolation and in combination. The dataset contains the concentration of key metabolites linked to the aerobic and anaerobic metabolism, expressed as ng metabolite per mg wet weight. Metabolite extraction, identification and quantification was carried out on shrimp muscle tissue by Les laboratoires Iso-BioKem Inc. in February/March 2021