Research Vessel Data Research Articles

Impacts of the Marine Technology Boom: Ocean Literacy Now Requires Data Literacy

New technologies are continually being placed in the ocean, constantly collecting ocean data in real-time. As a result, Data Literacy is now a necessary learning goal for supporting students' Ocean Literacy. The newest ships in the U.S. Academic Research Fleet, the Regional Class Research Vessels (RCRVs), are being built with the aim of supporting data literacy through outreach and education, with aid from a forthcoming real-time data portal. To understand how the RCRV’s outreach and education initiatives can best support data and ocean literacy, while also facilitating intentional engagement with minoritized populations, a three-phase research strategy was conducted over three years. The objective was to determine promising practices in data literacy education and shipboard outreach that are also culturally responsive. The first phase of the research interviewed experts in the fields of teaching, data literacy, shipboard education, and community engagement in order to generate recommendations. The second phase was an assessment of a three-day data literacy high-school curriculum utilizing research vessel data. The third phase examined the success of potential culturally responsive data literacy curricular frameworks and teaching practices in an afterschool pilot program for Latinx youth. The research determined that in a world where students have never ending access to data, data literacy education must be scaffolded throughout a student's life. Data used in education must be contextual and relatable and the best tools for data literacy learning are designed for teachers and students. As new knowledge is being generated about the ocean through new technologies continually collecting data, ocean literacy can no longer exist without data literacy.

Why Maritime Cybersecurity Is an Ocean Policy Priority and How It Can Be Addressed

AbstractMaritime cybersecurity is developing as an issue that affects the ocean. Recent security breaches cost shipping companies hundreds of millions of dollars and put marine ecosystems at risk by disabling ship controls and increasing risks of collisions and hazmat spills. Additionally, most new ships are designed to transmit engine performance data ashore to allow timely maintenance and efficient operation. However, many ships still prohibit such data transmission due to security concerns, resulting in increased ship emissions and environmental risks from accidental release of oil, hydraulic fluids, or lubricants. Similarly, research vessel data are routinely sent ashore, but security concerns for their computers are also increasing, especially when they operate in global ports and oceans. Maritime cybersecurity is also critical as autonomous ships are being developed. Addressing maritime cybersecurity is therefore a valid area of scientific policy research and important for ocean science operations.The International Maritime Organization (IMO) has called for improved maritime cybersecurity, and the U.S. Coast Guard also recently released a Navigation and Vessel Inspection Circular (NVIC; NVIC 05-17) on maritime cybersecurity for comments. The newly established Maritime Cyber Security Committee of the Marine Technology Society is coordinating maritime cybersecurity best practice information, contacts for cybersecurity professionals, and lessons learned on responding to cyberattacks to make this information broadly available. We review here various stakeholder approaches to maritime cybersecurity, outline available resources, and discuss how advanced methods, including optical communications and quantum encryption, will improve maritime cybersecurity. Scientists have a role in developing and implementing maritime cybersecurity methods and policies to ensure safe ship operations and improved environmental security for the oceans.

Gadoid dynamics: differing perceptions when contrasting stock vs. population trends and its implications to management

Recent research suggests that ICES stock definitions for cod, haddock, and whiting of “west of Scotland” and “North Sea”, do not reflect underlying population structures. As population responses to different vital rates and local pressures would be expected to lead to asynchrony in dynamics, we examined trends in local spawning-stock biomass (SSB) among putative subpopulations of the three species. Delineation of subpopulation boundaries around spawning time was made based on genetic, tagging, and otolith microchemistry studies together with density distributions of species based on research vessel survey data. Subpopulation specific indices of SSB were derived using numbers-at-age and maturity observations from the same research vessel data and asynchrony was assessed by fitting a smoother to log SSB for each subpopulation and testing whether the smooths were parallel. Results for cod support the hypothesis of distinct inshore and larger offshore subpopulations and for whiting for northern and southern North Sea subpopulations with a boundary associated with the 50 m depth contour. In haddock, no difference in SSB trends between the North Sea and west of Scotland was found. For cod and whiting, subpopulation SSB trends differed substantially within current stock assessment units, implying reported stock-based SSB time-series have masked underlying subpopulation trends.

The effectiveness of using CPUE data derived from Vessel Monitoring Systems and fisheries logbooks to estimate scallop biomass

Abstract Murray, L. G., Hinz, H., Hold, N., and Kaiser, M. J. 2013. The effectiveness of using CPUE data derived from Vessel Monitoring Systems and fisheries logbooks to estimate scallop biomass. – ICES Journal of Marine Science, 70: . Obtaining accurate data on abundance is vital to undertaking viable stock assessments of commercially exploited species. Satellite Vessel Monitoring Systems (VMSs) combined with fisheries logbooks have the potential to provide an abundant source of data with greater spatial and temporal coverage than research surveys. However, to date it has not been demonstrated how well VMS-derived abundance or biomass indices reflect research survey results. In this study we compared biomass indices of scallops derived from (i) fishing vessel surveys, (ii) research vessel surveys, and (iii) fishery-dependent data using VMSs and logbooks. In most cases there were strong relationships between biomass indices of Pecten maximus from fishing vessels and the research vessel. There were stronger relationships between P. maximus biomass indices from fishery-dependent VMS and logbook data and research vessel data at the beginning of the fishing season, when abundance was higher, but weaker relationships at the end of the fishing season. The time and location of sampling affected biomass estimates over short periods, and without standardizing to location and vessel, biomass depletion was masked. Fishery-dependent data provides a valid means of assessing relative scallop abundance and may prove equally viable in other fisheries with appropriate standardization of Catch Per Unit Effort (CPUE) data, making real-time management of fisheries increasingly feasible.

Estimating spatial and temporal variability of juvenile North Sea plaice from opportunistic data

Surveys are often insufficient to accurately capture the distribution of a species in both space and time. Complementary to the use of research vessel data, platforms of opportunity can be a powerful strategy to monitor species distributions at high temporal and spatial resolution.In this study we use data from commercial fishing vessels, collecting – under the European Union data collection framework – biological data on all species that are caught and subsequently discarded. Using such discard data in combination with a systematic trawl survey, we model the spatial and temporal distribution of juvenile plaice (Pleuronectes platessa) in the central North Sea. There is a clear age-dependent difference between the commercial fishing vessel data and the research vessel data, with age 1 being the dominating age in the survey catches, while age 2 is the dominating age in the discards. The results show how immature plaice, slowly migrate from the nursery areas, westwards into the deeper regions of the North Sea. Also, the results show that during the study period, juvenile plaice gradually moved to deeper waters at an earlier age. Finally we discuss how the framework can be applied to similar opportunistic data to monitor seasonal and inter-annual migration of marine organisms, and to quantify how they may be influenced by biotic and abiotic gradients, such as temperature.

Acoustic observations of micronekton fish on the scale of an ocean basin: potential and challenges

Abstract Kloser, R. J., Ryan, T. E., Young, J. W., and Lewis, M. E. 2009. Acoustic observations of micronekton fish on the scale of an ocean basin: potential and challenges. – ICES Journal of Marine Science, 66: 998–1006. Acoustic methods of characterizing micronekton communities (∼2 to 20 cm length) on the scale of an ocean basin could provide valuable inputs to ecosystem-based fishery management, marine planning, and monitoring the effects of climate change. The micronekton fish are important forage for top predators (e.g. tunas), and information on their diversity, distribution, size-structure, and abundance is needed to increase accuracy of top-predator distribution and abundance predictions. At the scale of an ocean basin, four years of Tasman Sea transects using a fishing vessel provide fine-scale maps of acoustic backscatter at 38 kHz that reveal detailed spatial patterns and structure to depths of 1200 m. Research-vessel data provide detailed biodiversity, density, size structure, and acoustic-scattering information from depth-stratified net sampling and a lowered acoustic probe. Wet-weight biomass estimates of the micronekton fish in the region vary considerably by a factor of 5–58 between acoustics (16–29 g m−2), nets (1.6 g m−2), and large spatial-scale, ecological models (0.5–3 g m−2). We demonstrate the potential and challenges of an acoustic basin-scale, fishing-vessel monitoring programme, including optical and net sensing, which could assist in characterizing the biodiversity, distribution, and biomass of the micronekton fish.

Bayesian survey-based assessment of North Sea plaice (Pleuronectes platessa): extracting integrated signals from multiple surveys

Abstract Bogaards, J. A., Kraak, S. B. M., and Rijnsdorp, A. D. 2009. Bayesian survey-based assessment of North Sea plaice (Pleuronectes platessa): extracting integrated signals from multiple surveys. – ICES Journal of Marine Science, 66: 665–679. Dependence on a relatively small sample size is generally viewed as a big disadvantage for survey-based assessments. We propose an integrated catch-at-age model for research vessel data derived from multiple surveys, and illustrate its utility in estimating trends in North Sea plaice abundance and fishing mortality. Parameter estimates were obtained by Bayesian analysis, which allows for estimation of uncertainty in model parameters attributable to measurement error. Model results indicated constant fishing selectivity over the distribution area of the North Sea plaice stock, with decreased selectivity at older age. Whereas separate analyses of survey datasets suggested different biomass trends in the southeast than in the western and central North Sea, a combined analysis demonstrated that the observations in both subareas were compatible and that spawning-stock biomass has been increasing over the period 1996–2005. The annual proportion of fish that dispersed in a northwesterly direction was estimated to increase from about 10% at age 2 to 33% at age 5 and older. We also found higher fishing mortality rates than reported in ICES assessments, which could be the consequence of inadequate specification of catchability-at-age in this study or underestimated fishing mortality by the conventional ICES assessment, which relies on official landings figures.

Surface and upper air meteorological features during onset phase of 2003 monsoon

The second campaign of the Arabian Sea Monsoon Experiment (ARMEX-II) was conducted in two phases viz., March–April and May–June 2003. In the present work, the buoy and ocean research vessel data collected during the second phase of ARMEX-II have been analysed to bring out the characteristic features of monsoon onset. The results have shown that the thermodynamical features such as build up of lower tropospheric instability and increased height of zero degree isotherm occurred about a week before the monsoon onset over Kerala and adjoining southeast Arabian Sea. There was a sharp fall in the temperature difference between 850 and 500 hPa, and the height of zero degree isotherm about 2–3 days before the monsoon onset. The flux of sensible heat was positive (sea to air) over south Arabian Sea during the onset phase. Over the Bay of Bengal higher negative (air to sea) values of sensible flux prevailed before the monsoon onset which became less negative with the advance of monsoon over that region.The pre-onset period was characterized by large sea surface temperature (SST) gradient over the Arabian Sea with rapid decrease towards north of the warm pool region. The buoy observations have shown that SST remained close to 30.5°C in the warm pool region during the pre-onset period in 2003 but only 2–3 degrees away (north of this region) SSTs were as low as 28.5–29°C. An interesting aspect of sea level pressure (SLP) variability over the Indian seas during the onset phase of summer monsoon 2003 was undoubtedly, the highest SLP in the warm pool region inspite of very high SSTs.

Analysis of the role of the ocean and the atmosphere in their thermal interaction based on satellite and research vessel data in the Newfoundland zone, North Atlantic

Analysis of the role of the ocean and the atmosphere in their thermal interaction based on satellite and research vessel data in the Newfoundland zone, North Atlantic

Did over-reliance on commercial catch rate data precipitate the collapse of northern cod?

Abstract It has been suggested that a number of “lessons” can be learned from the collapse of the northern cod stock off Newfoundland and Labrador. However, not all purported lessons have been validated with available data. One lesson is thought to be that over-reliance on commercial catch rate data and an incorrect assumption regarding the functional relationship between catch rate and population size were major contributors to overestimating stock size, precipitating the collapse. The current study describes calibration approaches used in assessments, and evaluates alternative functional relationships between commercial catch rates and stock size. In addition, historical population size is re-estimated using only research vessel data and compared with estimates obtained based on both commercial catch rate and research vessel data. Calibration with commercial catch rate contributed to overestimating stock size in some years, but there is no evidence that the assumed functional relationship between commercial catch rate and population size was a significant factor in the collapse.

Modelling the retention and survival of Browns Bank haddock larvae using an early life stage model

Browns Bank, the principal spawning ground for haddock on the south‐west Nova Scotian shelf, is composed of two distinct production zones: the inshore Bay of Fundy (BoF) region and the offshore south‐west Nova (SWN) bank region. Fish growing in the BoF are larger at age than those in the SWN region. Analysis of research vessel (RV) data shows that the majority of age‐2 haddock have the size of south‐west Nova Scotia fish, suggesting that the majority of surviving fish were retained in SWN. We used an early life stage (ELS) model to address two questions. First, we asked whether the length‐at‐age difference between Bof and SWN is evident at the larval stage. Using a temperature‐based growth model, we found that predicted size differences for late larvae would be less than 0.5 mm. From consideration of the average growth curves to age‐2 for the two regions, we showed that this difference was not the seed for the size difference in later life stage. The second question we addressed was how well the ELS model predicted partitioning of late larvae between SWN and the BoF corresponding to the ratio of SWN/BoF age‐2 juveniles found in the RV data. We ran the model on a representative number of years between 1973 and 1992, and found a significant correlation between the model simulation and the data (cor=0.71, P=0.047). This indicates that the age‐2 size distribution is a reflection of retention and survival occurring during the first two months of life. Model/data discrepancies are explained in terms of differential mortality between the two regions.

Fishing and the Ground-Fish Assemblage Structure in the North-Western North Sea: An Analysis of Long-Term and Spatial Trends

This paper examines long-term changes in the structure and composition of the groundfish species assemblage in three regions of the north-western North Sea. Scottish fisheries research vessel data collected during the months July-September over the period 1929-53 are compared with more recent August groundfish survey data covering the period 1980-93. Trends in the whole groundfish assemblage, and in a subset of the assemblage that is not targeted by commercial fisheries, are described. Long-term differences in species assemblage were subtle, and were most apparent in the dominance structure. Species diversity in the whole groundfish assemblage was marginally greater in the period 1929-53, but no difference was apparent within the non-target species assemblage. For the whole groundfish assemblage, diversity was greatest in the inshore region and least in the offshore area, but there was no obvious spatial gradient for the non-target species assemblage. Multivariate analyses indicated long-term changes and between-area differences in the species composition for both the whole groundfish assemblage and the non-target species subset. More detailed examination of the data revealed that the long-term changes resulted from relatively small and subtle differences in the relative abundance of rarer species, such as grey gurnard Eutrigla gurnardus (L.) and spur-dog Squalus acanthius L.. In contrast, changes in the relative abundance of the more common species, such as Norway pout Trisopterus esmarkii (Nilsson) and whiting Merlangius merlangus (L.), explained much of the between-area variation. Examination of species aggregated length-frequency distributions suggested that by the 1980s there had been a shift towards assemblages in which smaller fish were more highly represented. This was only apparent, however, in the whole groundfish species assemblage ; the length-frequency distributions of non-targeted species were almost identical in the two time periods. Overall, the results suggest that, although differences in the structure of the whole fish assemblage can be detected, the non-target groundfish assemblage appears to have remained relatively unchanged, despite a century of intensive fishing activity.

Recent Changes in Age and Size of Chum Salmon (Oncorhynchus keta) in the North Pacific Ocean and Possible Causes

Changes in age composition and size of adult chum salmon (Oncorhynchus keta) from rivers in Japan, Russia, and Canada were examined based on body weight and scale measurement data collected from 1953 to 1988. A significant increase in mean age was found in Japanese and Russian stocks after 1970 when the number of Japanese chum salmon began to increase exponentially, but not in the Canadian stock. Significant decreases in mean body weight, mean scale radius, and mean width of the third-year zones of age 4 chum salmon also occurred in Japanese and Russian stocks after 1970. Based on the Japanese salmon research vessel data from 1972 to 1988, significant negative relationships between catch-per-unit-effort and mean body weight of chum salmon were observed in summer in the central North Pacific Ocean where the distribution of Japanese and Russian stocks overlaps. These results suggest that density dependence is one of the possible causes for the recent changes in age and size of chum salmon in the North Pacific Ocean.

Changes in Size Distribution of Snow Crabs (Chionoecetes opilio) in the Southwestern Gulf of St. Lawrence

Size distributions of the exploited snow crab (Chionoecetes opilio) population in the southwestern Gulf of St. Lawrence were obtained from commercial landings in New Brunswick ports during 1977-82. The unexploited part of the stock was sampled during research vessel surveys in 1980 and 1981. The size distributions were analyzed by factorial analysis of correspondence. The trend in mean size was negative from 1977 to 1981 and positive thereafter. The analysis identified two periods of recruitment to the standing stock within each year: the first at the beginning of summer and the second in late summer and autumn. Growth of the previouslyrecruited crabs occurred between these two periods. Analysis of research vessel data indicated that many prerecruits inhabited areas outside the usual fishing grounds. The hypothesis is proposed of recruitment by platoons, with a part being due possibly to migration of crabs from shallow unexploited areas to deeper water where the commercial fishery occurs.

Interaction Between Stock Area, Stock Abundance, and Catchability Coefficient

The relationship between commercial catch-rates and population density upon which many stock assessment models depend assumes that stock area (A) is constant and independent of population abundance. Starting from a theoretical demonstration that the catchability coefficient (q) is inversely proportional to A, we establish the empirical basis of this relationship through comparisons of q and A of various Northwest Atlantic herring (Clupea harengus harengus) stocks and, in more detail, for Fortune Bay herring. For these stocks the relationship was of the form q = cA−b. For Atlantic herring stocks, levels of b were in excess of 0.80. In Fortune Bay herring, reductions in abundance were accompanied by proportional reductions in A, which in turn was inversely correlated with changes in q. School size, measured as catch per set, also declined as population levels declined but the change was not proportional. Published findings indicate that pelagic stocks in particular, and fish stocks in general, exhibit a common response of reductions in A with interactive increases in the q during periods of rapid population decline. We conclude that the conventional assumption of a constant stock area is usually violated due to the systematic interaction between A and population abundance which is reflected in an inverse relationship between stock abundance and q. Calibration of sequential population models should therefore be restricted to research vessel data collected in a standard manner and covering the distributional area of the stock.

Zones of coastal hypoxia revealed by satellite scanning have implications for strategic fishing

Hypoxic (oxygen concentrations <2.5mg l−1) and occasionally anoxic bottom waters occur along the inner continental shelf of Texas and Louisiana1–4. Little is known, however, about the spatial and temporal scales of these hypoxic areas. Boesch5 concludes the nearshore continental shelf west of the Mississippi River Delta has characteristics potentially favourable for large-scale bottom water oxygen depletion. These characteristics include influences from river and marsh discharges of freshwaters, rich in nutrients and sediments, The river effluent flows over the higher salinity shelf waters, creating two-layer vertical density stratification. When surface waters are heated during the summer, vertical stability increases, especially during calm wind periods, and vertical eddy diffusion is limited. Large-scale phytoplankton blooms stimulated by nutrients from the freshwater runoff can then produce large amounts of organic matter which sink and, through respiration and decomposition, deplete oxygen concentrations in the bottom layer. The hypoxia is normally limited to several metres of the water column next to the bottom6 in water depths usua <50m. Because hypoxia appears to be related to surface chlorophyll and temperature, which can both be measured with the Coastal Zone Color Scanner (CZCS) on board the Nimbus 7 spacecraft7,8, we have tried to determine if conditions favourable for formation of hypoxia could be detected and monitored from space. A linear discriminant function successfully identified areas of bottom water hypoxia detected by research vessels up to 10 days after satellite overpass. The discriminant function also successfully predicted hypoxic areas in June 1983 without resort to research vessel data. Shrimp and finfish were absent in the hypoxic zones; hence, the mapping from space of conditions favourable for hypoxia development may have significant marine resource implications for both strategic fishing and management.