Lunar Cycle Research Articles

Swoon over the moon: The influence of environmental factors on glass eels entering Mediterranean coastal lagoons

The European eel (Anguilla anguilla, Linnaeus 1758) is a critically endangered species that completes its life cycle between the freshwaters of Europe (and North Africa) and spawning grounds in the Sargasso Sea. Its marine larvae are planktonic and metamorphose into post-larval glass eels near the coast. The relationship between environmental variables and the migration of glass eels into brackish water and estuaries is not well understood, but has important implications for European eel conservation and management.Using linear mixed effects (LME) models, we investigated the combined role of meteorological (wind direction and strength and rainfall), oceanographical (tide amplitude), astronomical (moon phase and illumination), temporal and water quality variables on the timing and magnitude of glass eel migration from marine to brackish waters in the Comacchio Lagoon, Northern Adriatic Sea. We used this site as a test case because it was historically prominent in glass eel wild harvest for extensive aquaculture in the Mediterranean region.We found that meteorological factors and tide amplitude had a weak effect on the migration of glass eels into the lagoon. On the contrary, astronomical variables strongly influenced glass eel movement, with waxing phases and intermediate illumination enhancing movement towards the lagoon. We also identified at least two distinct migration pulses during our study period, which were not affected by temporal and water quality variables. Temporal and water quality variables affected body size of glass eels, with bigger glass eels caught later in the season. Identifying the importance of environmental variables affecting glass eels recruitment to brackish waters can help promoting eel stocks restoration through local management.

Where and when does the danger lie? Assessing how location, season and time of day affect the sequential stages of predation by lions in western Serengeti National Park

AbstractPredation is a fundamental ecological process influencing the distribution and abundance of animal populations and underlying how prey species perceive risk. The predation process is composed of four sequential stages – search, encounter, attack and kill – each of which has been used to describe risk across the landscape. Here, we used direct observational data of free‐ranging, radio‐collared African lions in Serengeti National Park's western corridor to (1) investigate daily and seasonal predation stage probabilities and (2) using two analytical approaches, compare four mechanisms – prey distribution, intra‐specific competition, spatially anchored landscape features and predator hunting method – that potentially drive spatial predation stage patterns. Results showed that lions encountered potential prey at night significantly less than during diurnal or crepuscular periods. Nocturnal observations were predominantly during full‐moon phases, so if this lower nocturnal encounter rate was due to moon phase it may contribute to lions' typically poor full‐moon hunting success. Predation stage probabilities did not differ between seasons despite high variability in seasonal prey abundance. Spatially, lions encountered potential prey in prey‐rich, open areas near water and spatial range centres. Compared with available areas within seasonal ranges, lion attacks were more likely where prey abundance was high, and kill locations were associated with prey‐rich areas near water and range centres, collectively suggesting opportunistic hunting. However, compared with preceding predation stage locations, attacks occurred near range peripheries and kills where hunting cover was greater, suggesting ambush predation. Our results indicate substantial temporal and spatial variation across the different stages of the predation process. They also highlight first, that results can vary in important ways depending on how analyses are approached, and second, that understanding predator‐prey dynamics depends on analyses of the different stages of predation.

Suicide risk over the course of the day, week, and life.

Suicide rates vary with important cycles in life, according to scientific findings and sometimes only according to lay beliefs. This paper reviews empirical studies on the association between suicides and a selection of cycles in life (the course of day, week, year, and life, menstrual cycle, and the moon phases). Non-systematic review with a selection of key-papers and recent reviews, and analyses of Austrian daily suicide data from 1970-2017. For the time of day, suicides occur slightly more frequently from morning to mid-day. However, among people awake, suicides peak during nighttime. For the course of the week, suicide rates increase on Mondays and decrease on weekends. Similarly, there are more suicides after major holidays. For the course of the year, suicide rates increase in spring/summer, decrease in December, are lowest on Christmas, peak on New Year's Day, and go back to about the yearly average thereafter. With respect to the life cycle, suicide rates are lowest in children and highest in elderly people, especially in men. Suicide rates increase during menstruation but not in the pre-menstruation phase. Suicide rates do not vary with moon-phases. There is robust evidence that suicide rates vary with some cycles in human life, such as day of the week, seasons and holidays, and there is some evidence that suicides vary with time of day and the menstrual cycle. Some of the associations seem counter-intuitive but can be explained with theories of suicides and related psychosocial mechanisms (e.g., the Broken Promise Effect). Since the effects are mostly small, findings cannot easily be translated into clinical practice but they enhance our understanding of suicides nonetheless.

Behavioural response of brown trout (Salmo trutta) to total dissolved gas supersaturation in a regulated river

AbstractTotal dissolved gas supersaturation from dams and power stations is a chronic freshwater pollutant that is toxic to animals with aquatic respiration. Laboratory ecotoxicology experiments have revealed capacity for captive fishes to saturoregulate by moving deeper, but field ecotoxicology research is largely lacking. We instrumented 94 brown trout in the Rysstad basin of the Otra River, Norway, with depth sensor acoustic transmitters and monitored their movements for 10 months. We found that the depths used by the trout largely protected them from the effects of total dissolved gas supersaturation, which ranged from 96% to 133% total gas pressure during the study. The depth use of fish was affected by sun position, lunar phase and spatial position in the river (i.e., available depth), and there was an extremely weak effect of total dissolved gas supersaturation that was counterintuitive (i.e., positive slope, movement toward surface). Depth traces of the fish revealed that nine fish died during the study, mostly coinciding with the first wave of supersaturation, consistent with observations of untagged dead fish with signs of gas bubble trauma found on the river bottom during this period (May‐June). Overall, tagged trout exposure to total dissolved gas supersaturation depended on their use of depth, but responses to waves of extreme supersaturation at supraphysiological levels were weak and biologically insignificant, with individual variation and spatial position in the river most important in the model. Exposure to total dissolved gas supersaturation was mediated by individual differences in habitat use, which may be linked to activity and other traits that determine overall vulnerability to exposure to total dissolved gas supersaturation.

Historical Sources on Epilepsy Surgery: From Antiquity Through the End 20th Century

The history of epilepsy is an associate of humanity, and the reports date back to antiquity. Almost all ancient cultures, including the Babylonians, Egyptians, Greeks, Indians in pre-Buddhist period, Iranians, Chinese, and Byzantine epoch, bear witness to epilepsy. Therefore, the earliest beginnings of surgical treatment and epilepsy surgery can be traced back to antiquity. Trepanation as an attempt to treat the disease has often been found in prehistorical tombs (Neolithicum). In antiquity, fasting, a healthy diet, regulation of excretions, medical gymnastics and a decent lifestyle were used as treatment for epilepsy as a non-surgical solution. In the Middle Ages, the basis for treatment fell into three main categories: Conventional (diet and botanical remedies), magical (phases of the moon, trephining of the skull) and religious beliefs (fasting, prayer, exorcisms, and social marginalization). The first neurosurgical operations on epileptic patients with focal semiology were performed during the early 19th century, and began with Godlee, Sommer, Macewen and later Horsley. From that time on, discoveries on epilepsy surgery progressed at a faster pace that started in a historical journey from ancient times until the end of the 20th century.

The Influence of Selected Meteorological Factors on the Prevalence and Course of Stroke.

Background: The objective of this study was to evaluate the impact of weather factors on stroke parameters. Methods: This retrospective study analyzed the records of stroke patients concerning the influence of meteorological conditions and moon phases on stroke parameters. Results: The study group consisted of 402 patients aged between 20 and 102; women constituted 49.8% of the subjects. Ischaemic stroke was diagnosed in 90.5% of patients and hemorrhagic stroke was diagnosed in 9.5% of patients. The highest number of hospitalizations due to stroke was observed in January (48 events); the lowest number was observed in July (23 events). There was no statistically significant correlation between the meteorological parameters on the day of onset and the preceding day of stroke and the neurological status (NIHSS) of patients. Mean air temperature on the day of stroke and the day preceding stroke was significantly lower in the group of patients discharged with a very good functional status (≤2 points in modified Rankin scale (mRS)) compared to the patients with a bad functional status (>2 points in mRS); respectively: 7.98 ± 8.01 vs. 9.63 ± 7.78; p = 0.041 and 8.13 ± 7.72 vs. 9.70 ± 7.50; p = 0.048). Humidity above 75% on the day of stroke was found to be a factor for excellent functional state (RR 1.61; p = 0.016). The total anterior circulation infarcts (in comparison with stroke in the other localization) were more frequent (70%) during a third quarter moon (p = 0.011). The following parameters had a significant influence on the number of stroke cases in relation to autumn having the lowest number of onsets: mean temperature (OR 1.019 95% CI 1.014–1.024, p < 0.000), humidity (OR 1.028, CI 1.023–1.034, p < 0.0001), wind speed (OR 0.923, 95% CI 0.909–0.937, p < 0.0001), insolation (OR 0.885, 95% CI 0.869–0.902, p < 0.0001), precipitation (OR 0.914, 95% CI 0.884–0.946, p < 0.0001). Conclusion: Air humidity and air temperature on the day of stroke onset as well as air temperature on the day preceding stroke are important for the functional status of patients in the acute disease period. A combination of the following meteorological parameters: lowered mean temperature and low sunshine, high humidity and high wind speed all increase the risk of stroke during the winter period. High humidity combined with high precipitation, low wind speed and low sunshine in the autumn period are associated with the lowest stroke incidence risk. A possible relationship between phases of the moon and the incidence requires further investigation.

Ovarian Development and Larval Release of the Hermit Crab Clibanarius eurysternus (Hilgendorf, 1879) (Decapoda: Anomura: Diogenidae) in Okinawa, Japan.

This study investigated ovarian development and larval release in the hermit crab Clibanarius eurysternus, which inhabits the upper intertidal zone on Okinawa, Japan. Adult females were collected monthly and had a high gonadosomatic index (GSI) from May to October. Oocytes at vitellogenic stages were observed from May to October. Some females had post-ovulatory follicles in the ovary and embryos on the abdomen (ovigerous females) in June and August, suggesting active ovarian development and larval release during these months (breeding season). When adult females were collected weekly according to the lunar cycle, a high GSI with oocytes at the tertiary yolk globule stage in the ovaries was maintained in all lunar phases. Since post-ovulated follicles were seen in ovaries collected around the last quarter and new moons, darkness at night is needed for spawning. Ovigerous females exposed to stepwise changes in hydrostatic pressure exhibited significantly higher synchrony between larval release and high pressure at night from the last quarter moon to the new moon, suggesting the importance of the tidal amplitude cycle in larval release under non-moonlight conditions. We concluded that the continuity of synchronous spawning and larval release of C. eurysternus are repeated under darkness and high tide at night during the breeding season.

The Effect of Lunar Phase on Squid Catches Using Flashing Led Lights: Pengaruh Fase Bulan Terhadap Hasil Tangkapan Pancing Cumi-Cumi Menggunakan Lampu Led Berkedip

The use of flashing LED lights on squid fishing rods to catch squids is still used by fishermen without concerning the lunar phase due to a lack of knowledge about the influence of the lunar phase on the squid catch. This study was conducted to 1. determine the effect of the lunar phase on the catch of squid using fishing rods, 2. compare the number of catches obtained using blue and white LED flashing lights. This experimental study was conducted using a Randomized Block Design (RBD). Data regarding squid catches (per squid) using blue and white LED lights were collected in 4 lunar phases. Data were then analyzed using variance analysis (ANOVA). Results showed that the lunar phase significantly affected the squid catching using fishing rods at a significance level of 0.05 (5%). Catches were significantly different in the new moon, first quarter, full moon, and third quarter phases. A higher number of catches was obtained in the third quarter phase compared to other phases. ANOVA test indicated a strong significant effect of the use of LED on the catch at a significant level of 0.05 (5%). The use of flashing blue LED resulted in a higher number of squid catches than white LED since squids were more attracted by blue light than white light.

Monitoring the brightness temperature of the Moon throughout the lunar cycle from radio observations in the Ku band

Within the spectrum of radio waves, the Ku band (12 - 18 GHz ) stands out for the wide range of instruments available and for its relative ease of acquisition, given that satellite television operates in this band. This situation offers a great opportunity for the development of radio astronomy in countries with unfavorable climatic conditions for optical astronomy, since this band is only affected by dense masses of water vapor. In this article we present a methodology for the calibration of the receiver system of compact Ku-band radio telescopes, and its application in the determination of the brightness temperature of the Moon. Our methodology involves modeling the influence of the atmosphere of the Earth on the response of the radioreceptor, which minimizes the error in the calculation of the brightness temperature of the observed object. We applied the proposed methodology in the monitoring of the Lunar cycle using the Ku-band radio telescope of the Observatorio Astronomico of Universidad Tecnológica de Pereira, Colombia (OAUTP). After observing during May, June, and July of 2021, we obtained an average temperature of 213.15 K, with maximum and minimum values of 275.55 K and 150.75 K, respectively. In addition, we evidenced a delay of 5.75 days between the phase in which the maximum temperature is presented and the phase of the full Moon, which is consistent with the frequency of observation. The results show that our methodology is useful to optimize the calibration of compact Ku-band radio telescopes, and expand the potential of this type of instrument for the scientific study of radio sources other than the Sun, in this case the Moon.

Lunar Tidal Effect on Equatorial Ionization Anomaly Region in China Low Latitude

AbstractThe equatorial ionization anomaly (EIA) crest derived from GPS observations, F2‐layer peak height (hmF2), critical frequency (foF2), and equatorial electrojet (EEJ) in China low latitude are used to study the lunar tidal effect on EIA region for the years from 2006 to 2015. A predominant 14.76‐day periodic component in EIA crest, hmF2, and EEJ concurrently appears in some seasonal intervals, which coincides with the half of the lunar revolution period (29.53 days) and the lunar phase, indicating that the 14.76‐day periodic oscillation in EIA region is modulated by the lunar tide. This 14.76‐day periodic oscillation occurs in all Northern Hemisphere (NH) winter and corresponds to their respective sudden stratospheric warming (SSW) period from 2006 to 2015. In addition, this 14.76‐day periodic oscillation also occurs in other seasons for some years, for example, May and August, in which wave power is sometimes comparable to that in SSW period. The occurrence of the 14.76‐day periodic oscillation and its wave power during non‐SSW seasons in the solar maximum years (2012–2015) is more frequent and higher than that in the solar minimum years (2008–2010). Our results suggest that, besides the NH SSW condition, the solar activity and some other unclear factors are also responsible for the lunar tide enhancement in EIA region.

An extended list of calendar anomalies in the context of the efficient market hypothesis

The efficient market hypothesis is commonly tested mainly with regard to capital markets, but it has also been applied to currency and commodity markets. Although the theory has been used to confirm that different markets vary in their effectiveness, certain cyclical anomalies can be observed in these markets. Particularly noteworthy are calendar anomalies, which can be used to develop investment methods and procedures. In addition to commonly known anomalies, such as the January or the December Effect, or short-term ones, like the Friday or Monday Effect, there are many others that are largely unknown in Poland, such as those related to the Presidential Election Cycle in the USA or very short-lived ones, associated with individual hours of investing in a trading session. The aim of the article is to present a possibly complete list of calendar anomalies recognized in foreign capital markets, but largely unknown in Poland, such as short-lived anomalies and exotic ones (e.g. related to phases of the moon).

Testing the waters to find the ‘goldilocks’ zone: fine-scale movement of

The fine-scale movement of Mustelus mustelus in relation to environmental conditions was investigated at various temporal scales with acoustic telemetry and temperature–depth transmitters inside a coastal marine protected area in South Africa. Twenty-four sharks were equipped with acoustic tags and logged by an array of 28 acoustic receivers from November 2006 to November 2008. Generalised additive and generalised additive mixed models (GAMMs) were used to explain patterns of movement in terms of the environmental conditions related to temperature, the rate of change of temperature, tidal flow, diel cycle and moon phase. The most important environmental parameters affecting movement and direction of movement were related to absolute temperature and changes in temperature at the position of the shark. The movement of M. mustelus was not affected by tide and only minimally affected by the diel cycle, suggesting behavioural thermoregulation as the ultimate cause of the movements. M. mustelus preferred temperatures from 18 to 22°C, as determined by GAMMs for environmental conditions experienced in summer. The combination of the thermal environment, rich feeding grounds and protective effect of the Langebaan Marine Protected Area may explain the high abundance and regular occurrence of M. mustelus within this marine protected area.

Age and lunar cycle predict harbor porpoise bycatch in the south-western Baltic Sea.

The harbor porpoise, Phocoena phocoena, is the only cetacean regularly occurring in the Baltic Sea. During the last decades, several anthropogenic activities have affected porpoises in the Baltic region. Most notably is bycatch in static fishing gear, such as gill nets, which is the main human-induced cause of death in odontocetes. There is still considerable uncertainty about which factors influence the amount of bycatch. In the present study, we reviewed bycatch data collected from 1987 to 2016 from the south-western Baltic Sea. There was a significant difference in bycatch due to seasonality and region, and there was a higher bycatch rate in juveniles than in adults. The only abiotic factor associated with bycatch was the lunar cycle, with more animals bycaught during a full moon. These results improve our understanding of which biotic and abiotic factors are associated with bycatch of Baltic harbor porpoises, which can be used to strengthen conservation endeavors such as managing fishing efforts.

Abundance dynamics of a new, endemic batoid from Brazil: The Lutz’s stingray, Hypanus berthalutzae

The Lutz’s stingray, Hypanus berthalutzae, is a recently identified, endemic dasyatid species which occurs in shallow habitats exclusively along most of the Brazilian coast. It is frequently caught as bycatch in different fisheries throughout the range of its distribution, but information on population trends and the impacts of fishing is still scarce. Therefore, this study aimed to describe the structure and dynamics in H. berthalutzae relative abundance off Recife, Northeast Brazil, in order to provide baseline data for species management. H. berthalutzae were caught and sampled in a fisheries-independent, standardized longline and drumline survey which used > 500,000 hooks during ∼11 years. H. berthalutzae catch composition (N = 86) was characterized by a striking predominance of females, with a female:male ratio of 16:1. Most of these individuals measured were considered to be mature. H. berthalutzae catch rates were largely reduced after hooks previously operating directly on the seafloor were suspended in the middle of the water column. Such an effect was included in a zero-inflated generalized additive model developed to assess spatiotemporal and environmental modulators of H. berthalutzae abundance, for which both month and lunar phase proved to be statistically significant predictors. A higher abundance of H. berthalutzae was observed in the rainy season, from March to July (χ2= 19.22; p < 0.001), as well as during full moon periods (Z = 2.38; p = 0.017). The effects of other candidate predictors such as sampling site or year were either nonexistent or superimposed by other more deterministic factors. The results achieved in this fully standardized survey depict the dynamics in adult H. berthalutzae which might be expected to occur in coastal habitats off northeastern Brazil, thus providing a solid contribution to improve the management of local artisanal fisheries towards the recovery and sustainability of H. berthalutzae populations across their range.

A hard day's night: Patterns in the diurnal and nocturnal foraging behavior of Apis dorsata across lunar cycles and seasons.

The giant honey bee Apis dorsata is unusual in being able to forage during both the day and the night. To date, the extent of this unique nocturnal foraging behavior and the environmental factors correlating with it have not been deeply investigated. We conducted the first systematic investigation into the nocturnal behavior of A. dorsata in Southern India by tracking the daily and nightly foraging activity of A. dorsata colonies in an urban environment for 8 months, over multiple seasons and lunar cycles. We found strong evidence that A. dorsata can behave in a manner that is “cathemeral” (active over the entire diel cycle) when environmental illumination is sufficient for nocturnal flight. However, workers were not always active even when the environment should have been bright enough for them to forage, suggesting that their nocturnal foraging behavior was also affected by seasonal changes in resource availability. The foraging activity observed during the day versus twilight versus night differed between seasons; notably, nocturnal activity rates were higher than diurnal activity rates during the winter. We found that at our study site A. dorsata routinely exhibits both diurnal and crepuscular activity, foraging just as intensely during the short twilight hours as during the day. The high foraging activity observed during the twilight and nighttime hours shows that A. dorsata colonies can extend their foraging beyond the daylight hours and reveals that foraging during these dimly lit hours is an integral part of their foraging ecology. This evidence of the importance of nocturnal and crepuscular foraging by A. dorsata paves the way for future studies examining the role of this species in nocturnal pollination networks, the contribution of nocturnal foraging to colony-level nutrition and energy budget, and the evolution of this unusual behavior. Future work comparing nocturnal activity in light polluted urban environments versus unpolluted natural environments is particularly encouraged to determine the generalizability of these findings.

Environmental cycles and individual variation in the vertical movements of a benthic elasmobranch

Trends in depth and vertical activity reflect the behaviour, habitat use and habitat preferences of marine organisms. However, among elasmobranchs, research has focused heavily on pelagic sharks, while the vertical movements of benthic elasmobranchs, such as skate (Rajidae), remain understudied. In this study, the vertical movements of the Critically Endangered flapper skate (Dipturus intermedius) were investigated using archival depth data collected at 2 min intervals from 21 individuals off the west coast of Scotland (56.5°N, −5.5°W) in 2016–17. Depth records comprised nearly four million observations and included eight time series longer than 1 year, forming one of the most comprehensive datasets collected on the movement of any skate to date. Additive modelling and functional data analysis were used to investigate vertical movements in relation to environmental cycles and individual characteristics. Vertical movements were dominated by individual variation but included prolonged periods of limited activity and more extensive movements that were associated with tidal, diel, lunar and seasonal cycles. Diel patterns were strongest, with irregular but frequent movements into shallower water at night, especially in autumn and winter. This research strengthens the evidence for vertical movements in relation to environmental cycles in benthic species and demonstrates a widely applicable flexible regression framework for movement research that recognises the importance of both individual-specific and group-level variation.

Exergy Analysis of Electrochemical Systems for Space Exploration

Human exploration of space, facilitated by electrochemical systems, will require integration of many seemingly disparate systems including but not limited to power systems, in situ resource utilization (ISRU), and environmental control and life support (ECLS). Through combining expressions of the First and Second Laws of Thermodynamics exergy quantifies the useful work that can be obtained from a system, subject to environmental limitations. This approach provides a means of integrating diverse systems and components based on one consistent and physically meaningful property: exergy. Using this property as a basis, diverse systems can be analyzed and integrated effectively based on the exergy destruction and exergy efficiency. Here, the applicability of exergy analysis to systems design and integration is demonstrated through two examples involving electrochemical systems that support human space exploration.First, analysis of the ECLS system aboard the International Space Station (ISS) is conducted to assess its overall performance in terms of exergy destruction rates and exergy efficiency. The ECLS system is divided into constituent subsystems which are further divided into key components. Based on this system decomposition, exergy balances are derived for each component and subsystem. Special focus is given to the Oxygen Generation Assembly (OGA) within the ECLS Atmospheric Revitalization Subsystem. The results of parametric studies of the OGA proton exchange membrane electrolyzer performance are presented with an emphasis on the impacts of operational conditions on exergy efficiency. This electrolyzer is a significant contributor to system exergy destruction and exhibits a low exergetic efficiency. It therefore presents an opportunity for improving overall ECLS system performance.Following the example of ECLS exergy analysis, the application of exergy analysis to the integration of power and ISRU systems for lunar exploration is presented through system level models. Exergy destruction and efficiency are quantified over the lunar diurnal cycle for power and ISRU systems. The power systems analysis focuses on photovoltaic arrays paired with battery and regenerative fuel cell systems. The ISRU system analysis focuses on production of oxygen from lunar regolith through the reduction of ilmenite combined with water electrolysis. Here the application of exergy analysis identifies key opportunities for the use of byproduct heat and the optimal sizing of system components.The studies presented demonstrate the capability of exergy analysis to support the design and integration of electrochemical systems within larger power, ISRU, and ECLS systems supporting space exploration. This approach can enable the full and efficient use of a system’s available work potential based on a consistent, physically meaningful property. Therefore, exergy analysis is shown to be a key tool for the future design and integration of electrochemical systems for space exploration.

Testis development in the Japanese eel is affected by photic signals through melatonin secretion.

ObjectiveAccording to reported spawning characteristics of Japanese eel, Anguilla japonica, which exhibit spawning and migration patterns that are synchronized with lunar cycles and photoperiod, we hypothesized that a close association exists between specific photic signals (daylight, daylength, and moonlight) and endocrinological regulation. Given the photic control in melatonin secretion, this hypothesis was tested by investigating whether melatonin signals act as mediators relaying photic signals during testis development in the eel.MethodsWe examined changes in melatonin-secretion patterns using time-resolved fluorescence immunoassays in sexually immature and mature male Japanese eels under the condition of a new moon (NM) and a full moon (FM).ResultsThe eye and plasma melatonin levels exhibited a nocturnal pattern under a 12-h light: dark cycle (12L12D) or under constant darkness (DD), but not with constant light (LL). Eye melatonin levels were similar under the 12L12D and short-day (9L15D) conditions. In the long-day condition (15L9D), secreted plasma melatonin levels were stable, whereas short-day melatonin secretion began when darkness commenced. Sexual maturation began at 8 weeks following intraperitoneal injection of human chorionic gonadotropin (hCG), and NM exposure led to significantly higher eye and plasma melatonin levels compared with those detected under FM exposure.

Relationship Between by Catch Ratio of Sardine-Anchovy Targeted Purse Seine and Some Environmental Factors Based on a General Addictive Model in the Aegean Sea

By catch is a serious conservation challenge for the fisheries whose viability is increasingly under threat. To approach maximum by catch reduction with minimum loss of targeted catch, fisheries need to have information on the environmental and anthropogenic factors in multi species seas like the Mediterranean. In this study, we used generalized additive models (GAM) to by the catch ratio of purse seine fishery to determine the effects of environmental variables. The data were collected during each fishing trip in the 2018-2019 fishing season that covers the time period between September 1st and April 15th. There were 26 species (66.216 mt in total) recorded as by catch and the rates of by catch species in the total by catch amount varied between 0.001% and 23.1%. In terms of habitat of by catch species, the total ratios of benthopelagic, demersal and pelagic species were 52% , 28% and 20%, respectively. Significant interactions observed indicate that the fluctuations in by catch ratios differed by depth and sea surface temperature, whereas the quarters of year and the moon phases were not found to affect by catch ratios significantly.&nbsp;

Drivers of zooplankton community composition in a novel ecosystem: Hawai'i mangroves as a case study

Abstract Management of established non‐native plants is challenging because removal is expensive and can produce negative consequences, yet establishment can create novel ecosystems. Red mangrove propagules were introduced to Moloka'i, Hawai'i, in 1902 to mitigate the effects of soil erosion and have since spread along the coast and to adjacent islands creating novel habitat. We compared zooplankton communities between novel mangrove and historical non‐mangrove habitat both within fishponds and along open coastline to examine environmental factors, including mangrove presence, affecting zooplankton community composition. Community composition patterns were driven by lunar cycle and site characteristics, including fishpond structure, mangrove and open‐coast shoreline length, percent of mangrove shoreline length, total percent mangrove leaf carbon and upstream watershed disturbance. Our findings indicate that during the tropical summer reproductive season, non‐native mangroves support diversity, richness and community composition similar to non‐mangrove areas, though some widespread taxa have lower abundance, and some rare taxa are more abundant in mangroves. Additionally, fishpond zooplankton community structure is significantly different from open‐coast areas, indicating fishponds, themselves, create novel habitat. Synthesis and application. In the face of declining fisheries, threatened reef habitat and changing climatic conditions, non‐native mangroves may provide, rather than impede, zooplankton habitat availability in novel locations.