Frontal Waters for the Growth of Engraulis Anchoita Larvae
Do Souto, M., Spinelli, M. L., Brown, D. R., Pájaro, M., Diaz, M. V., & Capitanio, F. L. (2018). Benefits of frontal waters for the growth of Engraulis anchoita larvae: The influence of food availability. Fisheries Research, 204, 181-188.
The authors investigate the relationship between the oceanographic characteristics and how they influence the growth of Engraulis anchoita larvae in the frontal waters. According to the authors, the main feature of frontal waters is the differential densities between two water masses, which results in convergence of the waters at the bottom boundary or the surface. These circulations and water convergence results in water stratification and nutrition enrichment, which generates favorable conditions for the development of phytoplankton, zooplankton, ichthyoplankton, and other top predators. To conduct the study, the investigators conducted their study along two transects, northern (NT) and southern transect (ST) on the oceanographic ship ARA Puerto Deseado. These areas have large larval concentrations, making them an ideal location for these studies. From these areas, varying samples of the different types of larva and other top predators are collected for use in conducting the study. The outcomes of the study indicate that there are various factors that determine the abundance of different types of larva. These factors include the values of chlorophyll-a concentration or the presence of halocline, which determine the presence of different types of larva. Chlorophyll-a concentration was higher in the Northern Transect than in the Southern Transect. The research findings indicate that maximum abundance of zooplankton was found at the low concentration chlorophyll-a patch, which is seen as a consequence of active feeding. Thus, the larval growth rates were higher in the NT than in the ST. This publication is significant as it increases the understanding the abundance and distribution of engraulis anchoita eggs and larval distribution at the frontal waters.
Mice Predation on Dark-Mantled Sooty Albatross
Cuthbert, R. J., Louw, H., Parker, G., Rexer-Huber, K., & Visser, P. (2013). Observations of mice predation on dark-mantled sooty albatross and Atlantic yellow-nosed albatross chicks at Gough Island. Antarctic Science, 25(6), 763-766.
The investigators explore some of the biological means that could be used to eradicate mice, which are considered as invasive species that can be destructive to the conservation efforts of different bird species. Mice predation has affected the breeding of different sea birds due to predation on chicks during the breeding season. This has caused the dark-mantled sooty albatross to become a globally endangered species of sea-birds as their eggs and chicks are invaded by mice. According to the study, the current predation levels are becoming unsustainable whereby more 65-80% of the chicks are killed during each season through mice predation. The dark mantled sooty albatross was studied through scan counts of the coastal and inland cliffs in Gough Islands. Most of the chicks that were killed during the winter and summer breeding season were found to have open wounds on their belly exposing intestines. In addition, a mouse hole leading to the nest was found suggesting that mice were preying on the chicks. According to the research findings, about 2-4% of the chicks. The findings indicate that the mice are preying on a larger number of the birds than the current observations indicate. This led to the decline in the number of sea-bird species, raising concerns over the need to control mice populations to minimize the severity they have on birds’ conservation in the environment. Thus, the publication is significant as it will help in determining how best to control the invasive mice species in the environment.
Mesoscale Aggregations and Spatial Distribution of Peruvian Anchovy
Moron, G., Galloso, P., Gutierrez, D., & Torrejon-Magallanes, J. (2018). Temporal changes in mesoscale aggregations and spatial distribution scenarios of the Peruvian anchovy (Engraulis ringens). Deep Sea Research Part II: Topical Studies in Oceanography.
The article investigates the impact of environmental factors and biomass levels on the on the spatial behavior of various species of fish, with a focus on Peruvian anchovy also called the Engraulis ringens. According to the publication, these species have a very dynamic spatial behavior in different spatial scales. This behavior affects the distribution of Peruvian anchovy in the environment. In Peru. This study aims at analyzing the temporal and spatial fluctuations of the various fish species based on acoustic data that focuses on large and meso-scale spatial structures. The study uses data from different scientific surveys and spatial Bayesian models in order to determine the spatial distribution of anchovy. As the investigators indicate, Peruvian anchovy hosts the largest mono-specific fishery in the world, which has benefited the economy. The results of the study indicate that there was no clear preference for any specific zone as some smaller areas were able to receive higher abundances. This suggests that the anchovy biomass may depend on the neighboring sites. In addition, there were structural changes in the time series if the species’ aggregative behavior while the spatial scenarios were highly influenced by the environment and seasonal changes such as El Nino events. In addition, the differences in the locations of the recurrent areas for each spatial scenario determined the presence and distribution of the species. The publication has played a significant role in helping understand the biomass distribution differences based on the biological and ecological differences of various regions.
Marine Debris Ingestion
Lavers, J. L., Hutton, I., & Bond, A. L. (2018). Ingestion of marine debris by Wedge-tailed Shearwaters (Ardenna Pacifica) on Lord Howe Island, Australia during 2005–2018. Marine Pollution Bulletin, 133, 616-621.
The authors explore the rate of plastic production over the years since the 1950s and how their disposal has affected the world’s oceans and water species. The release of plastic debris into the environment has significantly affected the health of the species in the ocean that ingest this debris. Inadequate and improper disposal of the plastic waste has resulted in an increase in the volume of plastic debris in our oceans, which has in turn seen sea species ingest these debris. The study focuses on the wedge-tailed shearwaters with the results indicating that the ingestion of plastic debris results in reduced health of these species. The study indicates significant variations in the volume of plastic debris ingested over time from 2005 to 2018. In addition, the study classifies the plastic debris in terms of colors. The study findings indicate that the birds studied select the plastic they ingest based on color. This publication is very important in determining the impact of plastic debris on the various bird species in as much as the study could be used in facilitating future studies on the impact of color on plastics ingested by these species. The interaction between wildlife and plastic debris has a negative impact on the environment as it increases the mortality rates of the animals due to entanglement, starvation, or dehydration due to blockage by the debris and the harm it causes to their digestive tract after ingesting plastic.
Reproduction of Brevooria Aurea
Lajud, N. A., Astarloa, J. M. D. D., & González-Castro, M. (2016). Reproduction of Brevoortia aurea (Spix & Agassiz, 1829) (Actinopterygii: Clupeidae) in the Mar Chiquita Coastal Lagoon, Buenos Aires, Argentina. Neotropical Ichthyology, 14(1).
The investigators sought to study the reproductive biology of the Brevoortia aurea (Clupeiformes) in Mar Chiquita Coastal Lagoon in relation to the environmental variables. The study estimates the main biological-reproductive parameters. According to the study, some fish species are able to tolerate low salinities in as much as they can enter the fresh water in order to feed. The members of Brevoortia aurea or Clupeids are marine, coastal, and schooling fishes that scatter pelagic eggs. To conduct the study, the investigators conducted studies on the fisheries in Mar Chiquita Coastal Lagoon, whose depth and salinity is significantly affected by the semidiurnal tidal regime. The fish samples are studied for reproductive period aimed at establishing the reproductive parameters given the variation in environmental variables, salinity, and turbidity of the water. The results of the study indicated that the selected species were able to tolerate a wide range of water salinities ranging from almost fresh water to the full-strength sea water. Water salinity does not affect the salinity patterns while water temperature varied from one season to the other affecting the abundance of the fish species. Low abundances were recorded during winter while higher abundances were recorded during summer. This publication is significant in helping researchers and scholars to understand the distribution patterns and maturity rates of the fish species in different regions within the lagoon.
Effect of Habitat Conditions on Reproduction of the European Anchovy
Basilone, G., Guisande, C., Patti, B., Mazzola, S., Cuttitta, A., Bonanno, A., & Maneiro, I. (2006). Effect of habitat conditions on reproduction of the European anchovy (Engraulis encrasicolus) in the Strait of Sicily. Fisheries Oceanography, 15(4), 271-280.
The study aims at describing the reproductive cycle of the Engraulis Enrasicolus also called the European anchovy in the south coast of Sicily. This would help determine the variations in intra- and inter-annual reproductive traits as well as their adaptive responses to help maximize the reproductive success of the various species in the environment. To do this, the investigators collected biological data from the purse seine and mid-water pelagic trawl fish caught in Sicily over a period of six years from 1997 to 2002. The results of the study indicate that the length-weight relationships of the selected anchovy were significantly affected by the availability of food prior to the time of spawning while their reproduction was limited by the low primary production in the area. The reproductive cycle and temperatures in the region were synchronous as the water warming marked the beginning of a high water stability while water cooling marked the beginning of low water stability. More reproduction takes place when the water column stability is higher, an environment that favors food concentration, egg, and larval retention thereby increasing the production in the area. This publication will contribute to the success of future studies and efforts to boost reproduction of the anchovy in Sicily.
Understanding Fragetta Storm-Petrels using Phylogenetic Analysis
Robertson, B. C., Stephenson, B. M., Ronconi, R. A., Goldstien, S. J., Shepherd, L., Tennyson, A., … & Ryan, P. G. (2016). Phylogenetic affinities of the Fregetta storm-petrels are not black and white. Molecular phylogenetics and evolution, 97, 170-176.
According to the article, Fragetta storm-petrels comprise of two main species namely black-bellied storm-petrels F. tropica and the white bellied storm petrels F. grallaria breed. Phylogenetic analysis helps understand how best to classify each of these species in the right category, or taxonomy. To conduct the study, the samples of blood and tissues from the birds were collected at their breeding localities. These samples were used extract DNA and conduct DNA sequence analysis. Genetic analysis is conducted to ensure that the geneious sequences can be determined for the organisms. The results of the study indicated that the white-bellied fragetta storm-petrels could be found in the Tristan da Cunha Islands and Gough Island. While the F. tropica clade was more limited to one location, the F. grallaria was more divergent and supports two subgroups. In addition, the findings from the phylogenetic analysis in the publication indicated that Fragetta storm petrels are classified in three main categories consistent with the traditional species of F.tropica and F. grallaria as well as the F. maoriana. This publication is significant as it will facilitate the development of greater knowledge about the distribution, abundance, and relationships among the organisms in the Fragetta taxonomy and understanding why F. grallaria and F. tropica have white bellies in regions where they both occur.
Methods for Catching Storm Petrels
Trull, P. F., Finnegan, S., & Gallagher, A. J. (2018). A new method for catching Wilson's Storm Petrels Oceanites oceanicus at sea. Marine Ornithology, 46, 125-127.
There are many species of oceanic birds. These birds migrate annually from their breeding grounds in the polar and subpolar southern hemisphere to the norther hemisphere during the non-breeding period. The challenge comes when researchers seek to conduct studies on these birds are it becomes really challenging to catch them. Due to the fact that these birds keep on migrating and often molting, catching them could cause harm to them as it results in stress and raises ethical concerns since the global seabird populations are already an endangered species given that they have declined up to an estimated 70% over the years between 1950 and 2010. To conduct the study, samples of these birds were collected and marked using the stainless steel band and pictures taken for record keeping. In addition, their age was determined by observing some of the bird’s features such as the shape of their primary and tail feathers. The results of the study showed that all the birds remained unharmed during and after being captured in as much as they flew off unabated after being released. The method used in catching the seabirds, using nets, proved successful and caused no harm or distress to the birds. This publication provides insights on how best to conduct research on endangered species and be able to capture them without causing any harm or major disruptions in their normal life. This is demonstrated by capturing storm petrels using nets, as they attracted to fish slicks, labeling them, and releasing them to avoid disrupting their migration and breeding patterns.
Effect of Plastic Pollution on Flesh-footed Shearwater Ardenna Carneipes Burrows
Paterson, H., & Dunlop, J. (2018). Minimal plastic in flesh-footed shearwater Ardenna carneipes burrows at southwestern Australia colonies. Marine Ornithology, 46, 165-167.
The investigators in this publication sought to explore the impact of exposure to plastic pollution on the flesh-footed shearwater Ardenna carneipes burrows at Southwestern Australia colonies. These birds have been declining around the world and their exposure to plastic waste increase the risk they face as an endangered species. To conduct the study, samples of food collected by these species was collected where plastic debris was found in the food the birds feed to their young ones. The results of the study indicate that there were minimal occurrences where plastic fragments were found in food and sand samples used by these species. This lack of plastic fragments was associated to the feeding behaviors of the birds as well as the availability of plastics in the local ocean waters. As such, the results of the study suggest that plastics are not necessarily the main problem facing nesting of the flesh-footed shearwater Ardenna carneipes burrows in this region. This publication is significant in helping to understand the cause of the declining numbers of the flesh-footed shearwater Ardenna carneipes among other seabirds.
Growth of Kelee Shad in the Coastal Waters of Pakistan
Panhwar, S. K., Liu, Q., & Siddiqui, G. (2013). Growth, mortality and stock assessment of kelee shad, Hilsa kelee (Fam: Clupeidae) in the coastal waters of Pakistan. Journal of ichthyology, 53(5), 365-371.
The article explores the growth, mortality, and stock of the Kelee Shad also called the Hilsa kelee in the coastal waters of Pakistan. The investigators sought to understand the trends in the pelagic fishery in Pakistan, which has been a key source of fish meal. The country has exported large amounts of shads to other countries thereby generating foreign income. Over the years, no specific tools have been provide to conduct population assessment for these species in the fisheries within the country. The study uses length-frequency-based stock assessment tools to conduct stock assessment and determine the growth and mortality patterns of the fish. The data collected indicate that the kelee shads in Pakistan reflect those from other countries where similar specifies can be found. From the study, the fisheries in the current market are at their optimal level and increasing fishery would only endanger the kelee shad species. Thus, the current levels of fishery should not be increased in the coastal water of Pakistan. This publication is important as it will contribute towards the conservation of the environment and ensure that kelee shads are not further endangered to extinction.