scholarly journals Swimming Abilities of Temperate Pelagic Fish Larvae Prove that they May Control their Dispersion in Coastal Areas

Diversity ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 185 ◽  
Author(s):  
Baptista ◽  
Morais ◽  
Cruz ◽  
Castanho ◽  
Ribeiro ◽  
...  

The Sense Acuity and Behavioral (SAAB) Hypothesis proposes that the swimming capabilities and sensorial acuity of temperate fish larvae allows them to find and swim towards coastal nursery areas, which are crucial for their recruitment. To gather further evidence to support this theory, it is necessary to understand how horizontal swimming capability varies along fish larvae ontogeny. Therefore, we studied the swimming capability of white seabream Diplodus sargus (Linnaeus, 1758) larvae along ontogeny, and their relationship with physiological condition. Thus, critical swimming speed (Ucrit) and the distance swam (km) during endurance tests were determined for fish larvae from 15 to 55 days post-hatching (DPH), and their physiological condition (RNA, DNA and protein contents) was assessed. The critical swimming speed of white seabream larvae increased along ontogeny from 1.1 cm s−1 (15 DPH) to 23 cm s−1 (50 and 55 DPH), and the distance swam by larvae in the endurance experiments increased from 0.01 km (15 DPH) to 86.5 km (45 DPH). This finding supports one of the premises of the SAAB hypothesis, which proposes that fish larvae can influence their transport and distribution in coastal areas due to their swimming capabilities. The relationship between larvae’s physiological condition and swimming capabilities were not evident in this study. Overall, this study provides critical information for understanding the link between population dynamics and connectivity with the management and conservation of fish stocks.

1995 ◽  
Vol 73 (11) ◽  
pp. 2165-2167 ◽  
Author(s):  
Alan S. Kolok ◽  
James T. Oris

The objective of this study was to test the hypothesis that the specific growth rate of male fathead minnows (Pimephales promelas) was positively correlated with swimming performance. Subadult fish were allowed to grow into adults over a period of 31 – 55 days, after which the critical swimming speed of each fish was determined. Variation in critical swimming speed was substantial (greater than 50%), and a significant positive correlation was found between number of growing days and critical swimming speed, whereas a significant negative correlation was found between specific growth rate and critical swimming speed. A multiple regression using specific growth rate and number of growing days explained over 47% of the variation in swimming performance. Fathead minnows that grow fast are poor swimmers, suggesting a trade-off between swimming performance and specific growth rate in this species.


The term ‘pollution’ is taken in its broadest sense and effects are recognized to be due to interference, tainting and toxicity. Each of these types of impact is discussed and assessed. It is concluded that no long-term adverse effects on fish stocks can be attributed to oil but that local impacts can be extremely damaging in the short term and that produce from specific localities can be tainted and unmarketable for long periods. In some coastal areas oil can be one among several contributors to reduced water quality, and the implications of this are discussed.


1967 ◽  
Vol 24 (11) ◽  
pp. 2339-2354 ◽  
Author(s):  
James E. Stewart ◽  
John W. Cornick ◽  
Diane M. Foley ◽  
M. F. Li ◽  
C. M. Bishop

Total serum protein values, hemocyte numbers, and muscle weights were determined for 216 intermolt lobsters immediately after their capture, and for 230 others held captive under a variety of dietary and environmental conditions. Average muscle values ranged from approximately 13% to the more normal 20–25% of the live animals' weight, depending upon experimental conditions. The total serum protein up to a level of 55 mg/ml was shown to be a reliable indicator of muscle weights, although the relationship was not identical for all lobster groups. It appeared to be modified chiefly by the areas from which the different groups were taken. Diet was more important than the temperatures (5 to 14 C) in affecting changes in muscle and serum protein values. Starvation caused a greater reduction (50 to 70%) in the size of the hepatopancreas than in the muscle. Histological examination of the hepatopancreatic tissue showed that the lipid content was markedly reduced upon starvation and that a degeneration of this organ was apparent for lobsters fed a beef liver and herring diet. Measurement of serum proteins would appear to be a useful technique in experiments on lobster nutrition and have value, within specified limits, for assessing the physiological condition of wild lobsters.


2021 ◽  
Vol 325 ◽  
pp. 01023
Author(s):  
Rizki Adriadi Ghiffari ◽  
Haryo Dwito Armono

Coastal erosion is the process of land erosion in coastal areas due to waves and ocean currents which reduce land and can adversely affect socio-economic activities in coastal areas. Coastal erosion risk assessment in the estuary is a development of previous research, because the erosion and accretion processes do not only occur along the shoreline, but also on the side facing river water bodies, due to the confluence of fluvial and marine processes. The landward shift of the shoreline in the Muara Asam Asam coastal area has reached 90 meters in the last 28 years, and has been detrimental because the area is a densely populated area with major economic activities in the fisheries and agriculture sectors. This study aims to determine the coastal erosion risk level zones based on the relationship among vulnerability and consequence parameters, through distance decay weighted based method. The results indicate that Muara Asam Asam has high risk zones of coastal erosion, especially in densely populated residential areas and dry land agriculture on the west side of the estuary, due to the lack of implementation of preventive measures through hard coastal structure and coastal zoning policy to protect socio-economic activities and coastal ecological environments.


2017 ◽  
Vol 14 (28) ◽  
pp. 17
Author(s):  
Elena Margarita Saccone

Resumen: Este artículo se propone indagar sobre la relación de los sambaquíes con el medio y las evidencias que los vinculan con una cultura marítima incluyendo el posible uso de la navegación por parte de los grupos que los produjeron. Las evidencias indirectas del uso de la navegación se relacionan, entre otros, con la ubicación de los sitios en zonas costeras, la complejidad de las sociedades que los construyeron, analogías etnográficas y hallazgos de cultura material vinculada con los elementos necesarios para producir embarcaciones. A través de la serie de evidencias indirectas planteadas se pretende afirmar que esta línea de trabajo debe ser profundizada ya que puede aportar una nueva mirada a las investigaciones sobre los grupos sambaquieros y podría conducir a una reinterpretación en particular sobre su movilidad.Abstract: This paper intends to explore the relationship between shell mounds and their environment and the evidence that relates them with a maritime culture, including the possible use of navigation by the groups who built them. Indirect evidence of navigation refers, among others, to the location of sites in coastal areas, the complexity of the groups that produced them, ethnographic analogies and material culture findings related to the necessary elements for the production of watercraft. Through this series of indirect evidences, we intend to state that this topic should be explored further because it can provide a new perspective on the research of shell mound groups and could lead to new interpretations especially about their mobility. 


Author(s):  
Roberto Baldassarre ◽  
Cristian Ieno ◽  
Marco Bonifazi ◽  
Maria Francesca Piacentini

Purpose: The sensation of fatigue experienced at a certain point of the race is an important factor in the regulation of pacing. The rating of perceived exertion (RPE) is considered one of the main mediators utilized by athletes to modify pacing. The aim was to analyze the relationship between pacing and RPE of elite open water swimmers during national indoor pool championships. Methods: A total of 17 elite open water swimmers (males, n = 9; females, n = 8) agreed to provide RPE every 500 m during the finals of the national championships 5-km indoor pool race. Time splits, stroke rate, and RPE were collected every 500 m. The Hazard score was calculated by multiplying the momentary RPE by the remaining fraction of the race. Athletes were placed in one of two categories: medalists or nonmedalists. For all variables, separate mixed analysis of variances (P ≤ .05) with repeated measures were used considering the splits (ie, every 500 m) as within-subjects factor and the groups (ie, medalists and nonmedalists) as between-subjects factor. Results: Average swimming speed showed a significant main effect for split for both males and females (P < .001). A significant interaction was observed between average swimming speed and groups for females (P = .032). RPE increased in both groups (P < .001) with no difference observed between groups. However, the female nonmedalists showed a disproportionate nonlinear increase in RPE (5.20 [2.31]) halfway through the event that corresponded to the point where they started significantly decreasing speed. Conclusions: The results of the present study show different pacing strategies adopted by medalists and nonmedalists despite a similar RPE.


2016 ◽  
Vol 7 (1) ◽  
pp. 198-204 ◽  
Author(s):  
David Deslauriers ◽  
Ryan Johnston ◽  
Steven R. Chipps

Abstract We assessed the effect of fin-curl on the swimming and station-holding ability of juvenile shovelnose sturgeon Scaphirhynchus platorynchus (mean fork length = 17 cm; mean weight = 16 g; n = 21) using a critical swimming speed test performed in a small swim chamber (90 L) at 20°C. We quantified fin-curl severity using the pectoral fin index. Results showed a positive relationship between pectoral fin index and critical swimming speed indicative of reduced swimming performance displayed by fish afflicted with a pectoral fin index &lt; 8%. Fin-curl severity, however, did not affect the station-holding ability of individual fish. Rather, fish affected with severe fin-curl were likely unable to use their pectoral fins to position their body adequately in the water column, which led to the early onset of fatigue. Results generated from this study should serve as an important consideration for future stocking practices.


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