Juvenile gadoids habitat association and ontogenetic shift observations using stereo-video baited cameras

Understanding habitat variables affecting species distribution and survival is essential to their protection. This is especially important in areas where anthropogenic pressures can have a significant direct impact on not only the survival of the species but also damage their habitat. The Firth of Clyde, southwestern Scotland, was an important commercial fishing area for a variety demersal fish species up until 1973. However, stocks have since declined to near-zero despite fisheries measures put in place to aid recovery. Here we report on Stereo Baited Remote Underwater Video (SBRUV) surveys in the Firth of Clyde between June and September in 2013 and 2014 to determine the habitat of juvenile Atlantic cod Gadus morhua, haddock Melanogrammus aeglefinus, and whiting Merlangius merlangus. Habitat predictor variables explored included substratum type, depth, wave fetch, and bentho-demersal species diversity. G. morhua were most abundant in shallow, sheltered areas composed of gravel-pebble containing maerl. Ontogenetic shifts and density dependence were also observed. M. aeglefinus, and M. merlangus predominated over deeper sand and mud. Relative abundances of all three species were positively related to bentho-demersal diversity. This work demonstrates the potential of SBRUV as a non-destructive survey tool under northern-temperate conditions. Our results indicate that spatial conservation measures to benefit demersal fish should be advised by patterns of bentho-demersal diversity as well as physical substratum types

Changes in the Norwegian Sea deep water

This paper deals with observed changes in the Norwegian Sea Deep Water (NSDW) after the cessation of bottom water formation in the Greenland Sea. Current measurements indicate that the deep water flow from the Greenland Sea to the Norwegian Sea has reversed. The Deep Water in the Norwegian Sea is warming in the entire layer below 1000m depth and down to the bottom. The thickness of the adiabatic layer is decreasing. The salinity of the homohaline layer is constant but the thickness is decreasing. The overflow water in the Faroe-Shetland Channel is freshening

Survival of the fittest: explanations for gadoid imbalance in heavily fished seas

1. Anthropogenic activities have caused the degradation of the world's ecosystems, accelerating the loss of biodiversity. In marine ecosystems, fishing has had strong impacts on fish populations and their habitats; however, not all species have responded equally to fishing pressure. 2. Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus), and whiting (Merlangius merlangus) are of high commercial value throughout the North Atlantic. Despite having relatively similar life cycles, the state of stocks of these three species varies enormously, with whiting faring better than cod. Within the Firth of Clyde (south‐west Scotland), this imbalance is especially accentuated, where small whiting now make up the greater proportion of the biomass. 3. In this study, cod, haddock, and whiting recruitment to coastal areas, growth, and bait attraction were explored within a marine protected area (MPA) in the Firth of Clyde. Over the course of the summers of 2013 and 2014, whiting and haddock arrived at coastal areas earlier than cod, and grew more quickly. Cod were on average the smallest gadoid observed, and whiting the largest. Whiting also had more predominant scavenging behaviour. 4. These results, in combination with other life‐history traits, indicate that whiting may be at a competitive advantage over cod, and this may partly explain the imbalance of gadoids in the Firth of Clyde. This study highlights the importance of considering life‐history differences in multi‐species fisheries management, and how appropriately managed MPAs could help to restore fish population and assemblage structure

Recent upper layer cooling and freshening in the Norwegian Sea

Several time series of temperature and salinity in the Norwegian Sea indicate a general upper layer decrease in both variables. The observations indicate that this change began in about the middle of the 1960s. Time series at Ocean Weather Station "M" (OWS"M"), from Russian surveys in the southem Norwegian Sea as well as Scottish and Faroese observations in the Faroe-Shetland Channel and around the Faroes, all have similar trends and show that this is a phenomenon which affects wide areas in the Norwegian Sea. The reason for this trend is an increased supply of freshwater in the East Icelandic Current. As a result, both temperature and salinity is now at a lower level than during the "Great Salinity Anomaly'' ("GSA") in the 1970s both at 400 m depth at OWS "M" and in the 200- 500 m layer in the southem Norwegian Sea as observed in the Russian time series. The forcing may be increased production of Arctic surface water in the Greenland Sea when the deep convection is reduced, or more probably, increased export of freshwater from the Arctic Ocean. There is fairly good correlation between the wind stress curl over the Greenland Sea and the Russian time series of temperature and salinity, averaged between 200 and 500 m depth and between O and 3.5°E along 63°N in the Norwegian Sea. Considerably increased supply of Arctic Water from the East Icelandic Current during a period around 1978, clearly reinforced the "GSA" in the Nordic Seas. This also explains the coinciding variation in Atlantic and Arctic waters in the Faroe-Shetland Channel during the "GSA"

Bases expert statement on the use of music for movement among people with Parkinson's

First published in The Sport and Exercise Scientist, February 2020, Issue 63. Published by the British Association of Sport and Exercise Sciences – www.bases.org.uk.Music is an artistic auditory stimulus that unfolds over time. It can prime specific actions and prompt engagement in physical activity as well as heighten motivation during motor tasks (Karageorghis, 2020). Contrastingly, it can be used to downregulate arousal to facilitate the transition from an active to a sedentary state or to ameliorate anxiety. In therapeutic applications, musical features such as rhythm, melody and harmony have been shown to elicit psychological and physiological changes (Thaut & Hoemberg, 2014). Parkinson’s is a degenerative neurological condition in which the loss of dopamine neurons results in impaired initiation and control of movement, with common symptoms including tremor, postural instability and gait disturbance. There are also non-motor effects that include apathy, anxiety and depression. Medication does not alleviate all manifestations of the condition and there is presently no known cure (Obeso et al., 2017). It is notable that people with Parkinson’s are estimated to be 30% less active than agematched peers (Ramaswamy et al., 2018). Nonetheless, evidence is emerging that a range of exercise-based and social activities that involve musical engagement can serve to address the common symptoms and enhance quality of life (Thaut & Hoemberg, 2014). This statement brings together an international interdisciplinary team to outline what is known about music-related applications for people with Parkinson’s, and to provide recommendations for exercise and health practitioners.Peer reviewe

A quasi-synoptic survey of the European continental shelf edge during the SEFOS project

Quasi-synoptic surveys of the European continental shelf edge have been conducted since the spring of 1994 by participants in the Shelf Edge Fisheries Oceanography Study (SEFOS). The purpose of the surveys is primarily to address questions concerning the eastern boundary current raised by fishery biologists, as the eastern boundary or slope current is intimately involved in the life history of many important European commercial fish species, such as mackerel, horse mackerel, blue whiting and hake. In all 21 sections were defined crossing the shelf edge from Portugal to Norway. The majority of these were occupied by a number of European laboratories between March and June 1994. Sections across the shelf edge have been used to examine the location and characteristics of the current in the different observational regions. Diagrams of t-S have been employed to describe the water masses involved in the slope current. Vertical and horizontal sections along the shelf have been constructed from the different across-shelf sections in order to examine the along-shelf variation of processes such as vertical and horizontal mixing in the area of the current. While preliminary data are presented, data collection continues and final analysis has not yet been completed

Modelling seabed sediment physical properties and organic matter content in the Firth of Clyde

High quality quantitative maps of seabed sedimentary physical and geochemical properties have numerous research and conservation applications, including habitat and ecosystem modelling, marine spatial planning and ecosystem service mapping. However, such maps are lacking for many ecologically and economically important marine areas. Using legacy data supplemented by measurements from recent benthic surveys, modelled hydrodynamic variables and high resolution bathymetry, quantitative maps for the top 10 cm of seabed sediment were generated via a combination of statistical and machine-learning techniques for the Firth of Clyde, a semi-enclosed coastal sea on the west coast of Scotland. The maps include sediment fractions of mud, sand and gravel, whole-sediment median grain size, sediment permeability and porosity, rates of natural seabed abrasion, and sediment particulate organic carbon and nitrogen content. Properties were mapped over an unstructured grid, so that very high resolutions were achieved close to the coastlines, where sediments may be expected to be spatially heterogeneous. Overall, the maps reveal extensive areas of very low sediment permeability coupled with low rates of natural seabed disturbance. Moreover, muddy sediments in the inner Firth of Clyde, Inchmarnock Water and the sea lochs are enriched in organic carbon and nitrogen relative to the sediments of the outer Firth of Clyde. As a demonstration of the value of these maps, the standing stock of organic carbon and nitrogen in the surficial sediments of the Clyde was calculated. The Clyde stores 3.42 and 0.33 million tonnes of organic carbon and nitrogen in the top 10 cm of seabed sediment, respectively, substantially contributing to Scotland’s coastal and shelf blue carbon stocks

Measured volume, heat, and salt fluxes from the Atlantic to the Arctic Mediterranean

The flow of warm and saline Atlantic water towards the Arctic crosses the Greenland-Scotland Ridge in three current branches. Since the mid 1990's, extensive monitoring with quasi-permanent moorings and regular CTD cruises has been in operation on three sections crossing the branches. Averaged over the years 1999 to 2001, values of volume, heat (relative to 0°C) and salt flux due to the total Atlantic inflow across the Greenland-Scotland Ridge into the Nordic Seas are estimated as 8.5 Sv (1 Sv = 106 m3·s−1), 313·1012 W, and 303·106 kg·s−1. In this period, the average temperature and salinity of the Atlantic inflow were 8.5°C and 35.25, respectively. Within the observational uncertainty, we do not find any significant seasonal variation of the volume flux, but a negative correlation between the inflow flux through the Faroe-Shetland Channel and through the other two gaps was indicated

Lunar nodal tide effects on variability of sea level, temperature, and salinity in the Faroe-Shetland Channel and the Barents Sea

The Faroe-Shetland Channel and the Kola Section hydrographic time-series cover a time period of more than 100 years and represent two of the longest oceanographic time-series in the world. Relationships between the temperature and salinity of Atlantic water from these two areas are examined in this paper, which also presents for the first time comparisons between them and annual mean sea levels in the region. The investigation was based on a wavelet spectrum analysis used to identify the dominant cycle periods and cycle phases in all time-series. The water-property time-series show mean variability correlated to a sub-harmonic cycle of the nodal tide of about 74 years, with an advective delay between the Faroe-Shetland Channel and the Barents Sea of about 2 years. In addition, correlations better than R=0.7 were found between dominant Atlantic water temperature cycles and the 18.6-year lunar nodal tide, and better than R=0.4 for the 18.6/2=9.3-year lunar nodal phase tide. The correlation between the lunar nodal tides and the ocean temperature variability suggests that deterministic lunar nodal tides are important regional climate indicators that should be included when future regional climate variability is considered. The present analysis suggests that Atlantic water temperature and salinity fluctuations in the Nordic Seas are influenced by forced tidal mixing modulated by harmonics of the nodal tide and influencing the water mass characteristics at some point "down stream" from the Faroe-Shetland Channel. The effects of the modulated oceanic mixing are subsequently distributed as complex coupled lunar nodal sub-harmonic spectra in the thermohaline circulation.</p