Monitoring Of Marine Resources Research Articles

The protection and development of marine resources under the perspective of the sustainable development concept

PurposeIn this study, suggestions on the protection and development of marine resources, sea area use and management, improvement of laws and regulations, monitoring of marine resources and impact assessment of marine environment are put forward.Design/methodology/approachLiterature research method.FindingsA major factor contributing to the decline in fishery resources is excessive fishing. At present, there are many problems to be solved in the exploitation and utilization of marine mineral resources in China. The pollution problem of marine tourism resources is becoming increasingly serious. Overmining of coastal sea resources has led to planning and management failures.Originality/valueThis paper discusses the current situation of marine resource exploitation and protection in China and analyzes the reasons for excessive resource exploitation from three aspects of marine concept, laws and regulations and marine management.

Establishing Natural Resources Monitoring Systems in China: Situation, Problem and Suggestion

Abstract. In order to fundamentally support work for achieve "climate action, life below water, and life on land" 3 Sustainable Development Goals of the United Nations, and to realize unified monitoring and refined management of natural resources, this paper collects, organizes, analyzes, and summarizes national policy, management department documents, relevant papers, and the latest industry development trends through the literature induction method. It systematically studies current monitoring networks from the perspectives of land resources monitoring, mineral resources monitoring, forest resources monitoring, grassland resources monitoring, water resources monitoring, wetland resources monitoring, marine resources monitoring. It indicates such problems as inconsistent classification standards and monitoring technical standards for natural resources, lack of smooth connection among monitoring networks, and insufficient high-tech applications. It proposes suggestions of building 1+N monitoring system, coordinating multi-level and multi-category monitoring mechanisms, improving monitoring intelligence level, strengthening the ability to obtain multi-source spatiotemporal data, and constructing an information sharing platform, to better build a unified natural resource monitoring system, and serve the refined management of natural resources.

Intelligent Detection of Marine Offshore Aquaculture with High-Resolution Optical Remote Sensing Images

The rapid and disordered expansion of artificial marine aquaculture areas has caused severe ecological and environmental problems. Accurate monitoring of offshore aquaculture areas is urgent and significant in order to support the scientific and sustainable management and protection of coastal marine resources. Artificial intelligence provides a valuable tool to improve marine resource monitoring. Deep learning methods have been widely used for marine object detection, but You Only Look Once (YOLO) models have not been employed for offshore aquaculture area monitoring. This study therefore evaluated the capacity of two well-known YOLO models, YOLOv5 and YOLOv7, to detect offshore aquaculture areas based on different high-resolution optical remote sensing imagery. Compared with YOLOv7 based on a satellite dataset, YOLOv5 increased the Precision value by approximately 3.29% (to 95.33%), Recall value by 3.02% (to 93.02%), mAP_0.5 by 2.03% (to 96.22%), and F1 score by 2.65% (to 94.16%). Based on the Google Earth dataset, YOLOv5 and YOLOv7 showed similar results. We found that the spatial resolution could affect the deep learning models’ performances. We used the Real-ESRGAN method to enhance the spatial resolution of satellite dataset and investigated whether super-resolution (SR) methods improved the detection accuracy of the YOLO models. The results indicated that despite improving the image clarity and resolution, the SR methods negatively affected the performance of the YOLO models for offshore aquaculture object detection. This suggests that attention should be paid to the use of SR methods before the application of deep learning models for object detection using remote sensing imagery.

Advances and development in sampling techniques for marine water resources: a comprehensive review

Marine water resources (including seawater and pore-water) provide important information for understanding the marine environment, studying marine organisms, and developing marine resources. Obtaining high-quality marine water samples is significant to marine scientific research and monitoring of marine resources. Since the 20th century, marine water resources sampling technology has become the key research direction of marine equipment. In order to have a comprehensive understanding of marine water resource sampling technology, promote the development of marine water resource sampling technology, and obtain high-quality marine water samples, this paper summarizes the current development status of the sampling technology of marine water resources from the aspects of research and application. This paper first provides an overview of seawater and pore water sampling techniques. The two sampling technologies are categorized and discussed according to different sampling means, and the advantages of different sampling means are compared. We also found similarities between seawater and pore water sampling means. Then, a comprehensive analysis of existing technologies and equipment reveals the development trend of marine water resources sampling technology, for example, the need for high temporal and spatial accuracy in sampling, etc. Finally, it explores the challenges facing deep-sea water sampling technology regarding future research, development and equipment industrialization. These reviews not only help researchers better understand the current development of marine water sampling technologies but also provide an important reference for the future development of marine water sampling technology, which provides guidance and support for in-depth marine scientific research and effective use of marine resources.

Reflecting on the recent history of coastal Maine fisheries and marine resource monitoring: the value of collaborative research, changing ecosystems, and thoughts on preparing for the future

AbstractThe Maine Department of Marine Resources (MEDMR) is a state agency tasked with developing, conserving, researching, and promoting commercial and recreational marine fisheries across Maine’s vast coastline. Close collaborations with industry members in each of the 30 or more fisheries that support Maine’s coastal economy are central to MEDMR’s efforts to address this suite of tasks. Here we reflect on recent decades of MEDMR's work and demonstrate how MEDMR fisheries research programmes are preparing for an uncertain future through the lens of three broadly applicable climate-driven challenges: (1) a rapidly changing marine ecosystem; (2) recommendations driven by state and federal climate initiatives; and (3) the need to share institutional knowledge with a new generation of marine resource scientists. We do this by highlighting our scientific and co-management approach to coastal Maine fisheries that have prospered, declined, or followed a unique trend over the last 25+ years. We use these examples to illustrate our lessons learned when studying a diverse array of fisheries, highlight the importance of collaborations with academia and the commercial fishing industry, and share our recommendations to marine resource scientists for addressing the climate-driven challenges that motivated this work.

Degradation-aware and color-corrected network for underwater image enhancement

Underwater image enhancement has played an important role in marine resource monitoring and preservation. However, the visual quality of underwater images is degraded due to light attenuation, background noise and water types, which brings challenging problems to underwater image enhancement. Existing Convolutional Neural Network (CNN) based methods do not fully explore degradation issues in different underwater scenes and also ignore color corrected priors, which limit their generalization and representation ability. To address the above mentioned problems, we propose a new Degradation-aware and Color-Corrected Network (DCN). Since it is difficult to estimate the degradation information of underwater image, we use Contrastive Learning (CL) to learn accurate degradation representation from input underwater images via a new degradation encoder. Then, to make the enhancement process adapt to different underwater images with the help of learned degradation representation and a color corrected prior, the DCN is built based on the proposed Degradation-aware and Color-corrected Block (DCB) for enhancing underwater images, which contains a degradation-aware branch, a color-corrected branch and an Edge Sharpness Layer (ESL). The degradation-aware branch recovers the clear image with the help of the degradation representation, while the color-corrected branch based on the color corrected prior compensates for the loss of information in the red channel. Furthermore, the ESL based on the unsharp masking principle is proposed and inserted at the end of the DCB for preserving details and sharpening edges. Such a design enables the DCN enhance underwater images, correct colors and sharpen edges simultaneously. The experiments on both synthetic and real images demonstrate that our method achieves pleasing visual results and outperforms state-of-the-art methods by a large margin.

Evaluation Methods of Change Detection of Seagrass Beds in the Waters of Pajenekang and Gusung Selayar

Knowledge about coastal and small island ecosystems is increasing for the monitoring of marine resources based on remote sensing. Remote sensing data provides up-to-date information with various resolutions when detecting changes in ecosystems. Studies have defined a shift in marine resources but were limited only to pixel or object classification in changes of seagrass area. In the present study, two classification method analysis approaches were compared to obtain optimum results in detecting changes in seagrass extent. It aimed to determine the dynamics of a seagrass ecosystem by comparing two classification methods in the waters of Gusung Island and Pajenekang, South Sulawesi, these methods being pixel-based and object-based classification methods. This research used SPOT-7 satellite imagery with 6 m2 of spatial resolution. Accuracy assessment using the confusion matrix showed optimum accuracy in object-based classification with an accuracy value of 87 %. Meanwhile, pixel-based classification showed an accuracy value of 78 % around Gusung Island. Pajenekang Island had accuracy values of 69 % with object-based classification and 65 % with pixel-based classification. A comparison of both classification methods revealed statistically high accuracy in mapping the benthic habitats of seagrass ecosystems. The results of the classifications showed a decline in the area of seagrass populations around Gusung Island from 2016 - 2018 and around Pajenekang Island from 2013 - 2017, with a change rate of 11.8 % around the island of Gusung and 7.6 % around the island of Pajenekang. This can explain the reason for the temporal method of object-based research classification having the best potential to process data changes in areas of seagrass in South Sulawesi waters and remote sensing information for the mapping of coastal area ecosystems.
 HIGHLIGHTS
 
 Information on coastal ecosystems globally with remote sensing data is currently very easy to access, but information related to ecosystem management and seagrass ecology in certain areas is still limited
 Analysis of seagrass benthic changes in shallow water requires data processing methods with high accuracy
 The OBIA (Object Based Image Analysis) method is one of the analytical methods that can provide optimal results in observing changes in seagrass ecosystems in the waters of South Sulawesi, Indonesia
 
 GRAPHICAL ABSTRACT

A Double-Transistor Double Primary–Winding Flyback Converter for Marine Resources Monitoring Equipment

Li, J.; Wu, H.; Xu, T., and Lin, P., 2020. A double-transistor double primary–winding flyback converter for marine resources monitoring equipment. In: Liu, X. and Zhao, L. (eds.), Today's Modern Coastal Society: Technical and Sociological Aspects of Coastal Research. Journal of Coastal Research, Special Issue No. 111, pp. 340–344. Coconut Creek (Florida), ISSN 0749-0208.The DC bus power-supply mode is the most convenient for marine resources monitoring equipment, and secondary electric power supplies at power supply nodes are featured by a wide variation range of input voltage and high electromagnetic interference (EMI) requirements. A double-transistor double primary–winding flyback converter with wide input range, low EMI noise, and active auto-starting function was designed in this study. The main circuit of this converter solves the withstanding voltage problem of switching tube via series connection of double transistors under high-voltage condition. Through the intertexture structure of the double primary windings, the main transformer reduces the drain-source voltage spike of the switch and effectively mitigates the common-mode EMI noise at output end. The large starting circuit loss is solved, and the converter efficiency is improved under wide input range through the active auto-starting circuit. The experimental results show that when the bus node voltage varies within a wide range of 100 V–1000 V, the converter efficiency is always greater than 85%, and EMI performance is superior, thus satisfying the requirements of bus power-supply system.

Local community-based approach for sustainable management of artisanal fisheries on small islands

Socio-economic development of small island fishing communities is greatly dependent on local coastal and marine resources. Illegal fishing and aggressive practices in insular ecosystems lead to overexploitation and environmental deterioration. Moreover, a lack of scientific data increases uncertainty and prevents adequate monitoring of marine resources. This paper focuses on the integration of a local fishing community into decision-making processes with the aim to potentiate artisanal fishing on the Island of Tenerife (the Canary Islands). The aim is to preserve both the marine ecosystem and promote the socio-economic development of traditional Cofradías (local fisher communities).A qualitative methodological framework, based on participatory problem-solution trees and focus groups, was implemented to identify the main obstacles impeding the sustainable development of the artisanal fishing sector on the island. Collective proposals with policy implications are also discussed.The community involved identified four main issues that are causing an unsustainable island fishery: 1) Overexploitation; 2) Poor self-management of Cofradías and commercialisation problems; 3) Fisher individualism and low co-management strategies, and 4) Illegal fishing increase vs. artisanal fishing decline. Results show the required policy enhancements to tackle those issues with, for instance, the creation of marine protected areas, the promotion of a common islander vision, and an increase in participatory research projects between scientists and fishers. Participants also revealed the necessity to adapt existing regulations to local specificity to reduce the gap between policy makers and local community.

Participatory artisanal fisheries management in islands: Application to the Canary Islands (Spain)

Socio-economic development of small-island fishing communities is greatly dependent on local coastal and marine resources. However, illegal fishing and aggressive practices in insular ecosystems lead to over-exploitation and environmental deterioration. Moreover, a lack of scientific data increases uncertainty and prevents the adequate monitoring of marine resources. This paper focuses on the integration of local fishing communities into decision-making processes with the aim of promoting artisanal fishing on the Island of Tenerife (the Canary Islands), as a way to preserve the marine ecosystem and socio-economic development of traditional cofradias (fishers' organisations). A qualitative methodological framework, based on participatory problem-solution trees and focus groups, was used to identify the main factors impeding the sustainable development of the artisanal fishing sector on the island and to elaborate collective proposals with policy implications. The fishing community involved identified four main issues that are maintaining an unsustainable island fishery: 1) Over-exploitation; 2) Poor self-management of cofradias and commercialisation problems; 3) Fisher individualism and low co-management strategies, and 4) Illegal fishing increase vs. artisanal fishing decline. Results show the required policy enhancements to tackle them and the need to adapt regulations to the local situation.

Testing marine conservation applications of unmanned aerial systems (UAS) in a remote marine protected area

In 2014, the United States National Oceanic and Atmospheric Administration (NOAA) utilized unique partnerships with the National Aeronautics and Space Administration (NASA), and the US Coast Guard for the first comparative testing of two unmanned aircraft systems (UAS): the Ikhana (an MQ-9 Predator B) and a Puma All-Environment (Puma AE). A multidisciplinary team of scientists developed missions to explore the application of the two platforms to maritime surveillance and marine resource monitoring and assessment. Testing was conducted in the Papahānaumokuākea Marine National Monument, a marine protected area in the Northwest Hawaiian Islands. Nearly 30 h of footage were collected by the test platforms, containing imagery of marine mammals, sea turtles, seabirds, marine debris, and coastal habitat. Both platforms proved capable of collecting usable data, although imagery collected using the Puma was determined to be more useful for resource monitoring purposes. Lessons learned included the need for increased camera resolution, co-location of mission scientists and UAS operators, the influence of weather on the quality of imagery collected, post-processing resource demands, and the need for pre-planning of mission targets and approach to maximize efficiency.

Sustaining the world's large marine ecosystems

Abstract In this essay, I review nearly six decades of a career in marine science and fisheries considering scientific contributions, successes, failures, and changes in my field of practice. My body of work has been in plankton research to support fisheries assessments, and in ecosystems programme development and implementation. I describe my early studies on Pacific plankton oceanography in relation to fisheries assessment, and subsequent studies of plankton oceanography and fisheries in relation to coastal ocean fisheries and management. Early in my career, realizing that applications of my published results and those of other fisheries ecologists were generally not included in fish stock assessments, I participated in a national planning group that introduced a system for marine resources monitoring, assessment, and prediction (MARMAP) that included primary productivity, ichthyoplankton, zooplankton, and oceanographic assessments as important components for large-scale fisheries ecology assessment. I joined with European colleagues in ICES to advance fisheries ecology studies in fish stock assessments in the 1970s and 1980s. In 1983, I conceived with Professor Lewis Alexander of the University of Rhode Island a system for assessing and managing marine resources within the spatial domain of ecologically delineated large marine ecosystems (LMEs). On behalf of the National Oceanic and Atmospheric Administration, and in partnership with developing countries, international financial organizations, UN agencies, and NGOs, I am currently contributing scientific and technical advice to a global network of assessment and management projects in 22 LMEs with 110 developing countries and $3.1 billion in financial support. The participating countries are applying a modular framework of natural science and social science indicators for assessing the changing states of LMEs. I conclude the essay with a retrospective viewpoint on my career and changes over half a century of practicing the application of marine science in relation to sustaining the goods and services of the ocean Commons.

Comparison of the Sameoto, Manta, and MARMAP neustonic ichthyoplankton samplers in the Gulf of Alaska

A comparison of three types of neuston-sampling gear, the Sameoto, the Manta, and the Marine Resources Monitoring, Assessment, and Prediction Program (MARMAP) array was conducted to examine and understand the effectiveness of each sampler in collecting larval fishes in the Gulf of Alaska. Comparison criteria included: number of individuals collected, assemblage diversity, and lengths of larvae. The MARMAP array had lower overall abundance compared to the Sameoto and Manta arrays. Species diversity was comparable among the gears, though the MARMAP array had a slightly higher and more evenly distributed range of taxa compared to the Sameoto and Manta arrays. Larval lengths were statistically comparable among gears, though the MARMAP array had relatively fewer large larvae compared to the Sameoto and Manta arrays. Based on these results, choice of gears should be considered depending on whether the primary objective is to obtain estimates of abundance or estimates of diversity.

Age, Growth, and Reproduction of Greater Amberjack off the Southeastern U.S. Atlantic Coast

AbstractThe greater amberjack Seriola dumerili is a pelagic, epibenthic species that is widely distributed in the Atlantic, Pacific, and Indian oceans. Life history samples from a total of 2,729 greater amberjacks were collected between 2000 and 2004 by personnel of the Marine Resource Monitoring Assessment and Prediction program and National Marine Fisheries Service port agents from recreational fisherman and in commercial fish houses from Cape Lookout, North Carolina, to Key West, Florida. Ages were estimated using thin transverse otolith sections from 1,996 specimens; sex and reproductive state were assigned to 2,517 fish based on histological preparations of gonadal tissues. Ages of greater amberjacks sampled ranged from 1 to 13 years; these data were described with a von Bertalanffy growth equation fitted to all aged specimens: Lt = 1,241.5 × [1 − e−0.28(t+1.56)]. Sexual dimorphism was evident; females were larger at age than males. Size at 50% maturity was 644 mm fork length (FL) for males and 733 mm FL for females. Age at 50% maturity for females was 1.3 years. Estimates of potential annual fecundity ranged from 18,271,400 to 59,032,800 oocytes for 930‐1,296‐mm specimens and from 25,472,100 to 47,194,300 oocytes for ages 3‐7. Peak spawning occurred primarily off south Florida and the Florida Keys during April and May. Even though the extremely fast growth, early maturation, very high fecundity, and wide distribution of greater amberjacks suggest that the population would be difficult to overexploit, a recent stock assessment of the Gulf of Mexico population shows that the species is vulnerable to overexploitation and should managed more conservatively than the life history characteristics imply.

Biomarkers and bioassays for detecting dioxin-like compounds in the marine environment

The presence of toxic chemical contaminants in some marine organisms, including those consumed by humans, is well known. Monitoring the levels of such contaminants and their geographic and temporal variability is important for assessing and maintaining the safety of seafood and the health of the marine environment. Chemical analyses are sensitive and specific, but can be expensive and provide little information on the actual or potential biological activity of the contaminants. Biologically-based assays can be used to indicate the presence and potential effects of contaminants in marine animals, and therefore, have potential for routine monitoring of the marine environment. Halogenated aromatic hydrocarbons (HAHs) such as chlorinated dioxins, dibenzofurans, and biphenyls comprise a major group of marine contaminants. The most toxic HAHs (dioxin-like compounds) act through an intracellular receptor protein, the aryl hydrocarbon receptor, which is present in humans and many, but not all, marine animals. A toxic equivalency approach based on an understanding of this mechanism provides an integrated measure of the biological potency or activity of HAH mixtures. Biomarkers measured in marine animals indicate their exposure to these chemicals in vivo. Similarly, in vitro biomarker responses measured in cell culture bioassays can be used to assess the concentration of ‘dioxin equivalents’ in extracts of environmental matrices. Here, I have reviewed the types and relative sensitivities of mechanistically-based, in vitro bioassays for dioxin-like compounds, including assays of receptor-binding, DNA-binding and transcriptional activation of native (CYP1A) or reporter (luciferase) genes. Examples of their use in environmental monitoring are provided. Cell culture bioassays are rapid and inexpensive, and thus have great potential for routine monitoring of marine resources, including seafood. Several such assays exist, or are being developed, for a variety of marine contaminants in addition to the dioxin-like chemicals. A battery of cell culture bioassays might be used to rapidly and sensitively screen seafood for the presence of contaminants of concern, including dioxin-like compounds as well as other contaminants such as natural toxins, hormonally active agents, and heavy metals. Such a battery of mechanism-based, in vitro bioassays could be incorporated into monitoring efforts under recently adopted hazard analysis and critical control point (HACCP) programs.

A new technique for monitoring the behaviour of free-ranging Adélie penguins.

Measurement of the time allocation of penguins at sea has been a major goal of researchers in recent years. Until now, however, no equipment has been available that would allow measurement of the aquatic and terrestrial behaviour of an Antarctic penguin while it is commuting between the colony and the foraging grounds. A new motion detector, based on the measurement of acceleration, has been used here in addition to current methods of inferring behaviour using data loggers that monitor depth and speed. We present data on the time allocation of Adélie penguins (Pygoscelis adeliae) according to the different types of behaviours they display during their foraging trips: walking, tobogganing, standing on land, lying on land, resting at the water surface, porpoising and diving. To illustrate the potential of this new technique, we compared the behaviour of Adélie penguins during the chick-rearing period in a fast sea-ice region and an ice-free region. The proportion of time spent standing, lying on land and walking during foraging trips was greater for penguins in the sea-ice region (37.6+/-13.3% standing, 21.6+/-15.6% lying and 5.9+/-6.3% walking) than for those in the ice-free region (12.0+/-15.8 % standing, 0.38+/-0.60% lying and 0 % walking), whereas the proportion of time spent resting at the water surface and porpoising was greater for birds in the ice-free region (38.1+/-6.4% resting and 1.1+/-1.1% porpoising) than for those in the sea-ice region (3.0+/-2.3% resting and 0% porpoising; means +/- s.d., N=7 for the sea-ice region, N=4 for the ice-free region). Using this new approach, further studies combining the monitoring of marine resources in different Antarctic sites and the measurement of the energy expenditure of foraging penguins, e.g. using heart rates, will constitute a powerful tool for investigating the effects of environmental conditions on their foraging strategy. This technique will expand our ability to monitor many animals in the field.

Cod and haddock spawning on Georges Bank in relation to water residence times

The seasonal and geographical patterns of spawning for Georges Bank cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) are estimated using composite distributions of stage I eggs derived from the Marine Resources Monitoring, Assessment and Prediction (MARMAP) data set (1977–1987). The inferred mean spawning locations are compared with patterns in particle residence times derived from a three‐dimensional prognostic circulation model that estimates the tidal and seasonal mean circulation. The comparisons indicate that cod and haddock spawning occurs at times and locations characterized by model residence times in excess of 35 d. The results are discussed in the context of fish population regulation theory, particularly the member/vagrant hypothesis and the concept of abundance‐dependent vagrancy.

Bergen acoustic buoy (BAB)—A tool for remote monitoring of marine resources

Marine resource abundance monitoring is often accomplished by means of research vessel acoustic surveys. Vessel time is limited and expensive, and optimal and cost-efficient utilization is required. Such vessels have clear limitations in observing the true acoustic distribution, density, and acoustic properties of marine organisms due to noise and light emitted during surveying and sampling. A potential solution to some of the emerging problems is a remote operated acoustic device, which can be used to monitor distribution, density, movements, and properties of marine organisms under natural and survey vessel affected conditions. In this paper a new concept for a remote operated acoustic data logger is presented which can give an online presentation of the acoustic information. The system is built on the new Simrad General Purpose Transceiver (GPT) operated through a standard windows NT interface. The technical specification and operational features will be presented and exemplified with experience from the first sea trials. The system is designed to meet demands from other applications, e.g., a drop sonde and towed underwater function, and future development of the concept is discussed.

Geographical range and taxonomic divergence in North Atlantic Calanus (C. helgolandicus, C. finmarchicus and C. glacialis)

The known distribution of Calanus helgolandicus in the North Atlantic Drift is difficult to explain in the absence of a reproductively active population inhabiting continental waters off eastern North America. New evidece indicates that this population, overlooked in the past, does in fact exist. The species has been found in a study of zooplankton samples from a number of MARMAP (Marine Resource Monitoring, Assessment, and Prediction Program) cruises surveying ichthyoplankton between Cape Hatteras and the New York Bight. Sexual activity in these stocks of C. helgolandicus was indicated by the ripeness of ovaries, the frequency of males, the presence of sperm in the females' seminal receptacles and the appearance of a female bearing a Calanus spermatophore. The new records provide a likely origin for the presence of the species in the vicinity of the Labrador Grand Banks as well as further east in the North Atlantic Drift. C. finmarchicus, similarly sexually active, was found to be sympatric with C. helgolandicus in the MARMAP collections which were taken from a region contiguous with the southernmost, known distribution, of C. glacialis. The distribution of integumental organs (i.e., pore signature patterns) was examined in the three species to determine whether they would be taxonomically useful. Strikingly different patterns were found on the female urosome. Pore signature differences between the polar species C. glacialis and the temperate C. helgolandicus proved to be as pronounced as those between the boreal C. finmarchicus and its two neighboring species. The successively overlapping ranges and the distinctive differences in pore signature patterns suggest that divergence from the generic pattern of integumental organ distribution has been a product of selection against hybridizing among the three species. If this is in fact the case, the reproductive range of C. helgolandicus has overlapped with those of C. finmarchicus and C. glacialis for appreciable periods in the history of the three species.

Marine population to be appraised in ocean survey

The National Oceanic and Atmospheric Administration has organized the Marine Resources Monitoring, Assessment, and Prediction Program (MARMAP), a national program to evaluate the living marine resources of waters off the United States. Also involved in the MARMAP project are government agencies and components of NOAA, several international marine organizations, almost a dozen state universities, and a number of research vessels from other nations.The first set of seasonal cruises by NOAA fleet vessels Albatross IV, Delaware II, and Oregon II will cover 19,000 miles from the Gulf of Maine to the northern Caribbean Sea, and will be completed early in 1973. Their purpose is to assess distribution of fish eggs and larvae (ichthyoplankton).