scholarly journals A long-term, spatially replicated experimental test of the effect of marine reserves on local fish yields

2005 ◽  
Vol 62 (1) ◽  
pp. 98-108 ◽  
Author(s):  
Angel C Alcala ◽  
Garry R Russ ◽  
Aileen P Maypa ◽  
Hilconida P Calumpong
Keyword(s):  
Coral Reefs ◽  
Experimental Test ◽  
Marine Reserves ◽  
Fish Biomass ◽  
Total Catch ◽  
Target Fish ◽  
Fish Yields

Do no-take marine reserves affect fishery yields? Manipulations of reserve status, and yield estimates, were made at two Philippine islands over two decades. Twenty-five percent and ten percent, respectively, of the coral reefs at Sumilon and Apo islands were made no-take reserves in 1974 and 1982. Biomass of target fish increased inside the no-take reserves 3- to 4.5-fold over 9–18 years. Biomass did not increase outside each reserve. Protection of the Sumilon reserve ceased in 1984. Biomass of targeted fish in the reserve and trap and gillnet catches of these fish declined by 42.7% and 40%, respectively, by 1985. The reserve was reprotected from 1987 to 1991 and from 1995 to 2001. Fish biomass increased in the reserve by 27.2%. Trap and gillnet catches outside the reserve increased 26.9% by 2001. The Apo reserve was protected from 1982 to 2001. Total catch of major fish families was significantly higher after (1985–2001) than before (1981) reserve establishment at Apo, increasing 41.3% between 1981 and 1998–2001. These experiments, plus spillover evidence, suggest that marine reserves may help maintain, or even enhance, local fishery yields in the long-term.

scholarly journals Gravity of human impacts mediates coral reef conservation gains

2018 ◽  
Vol 115 (27) ◽  
pp. E6116-E6125 ◽  
Author(s):  
Joshua E. Cinner ◽  
Eva Maire ◽  
Cindy Huchery ◽  
M. Aaron MacNeil ◽  
Nicholas A. J. Graham ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Human Impacts ◽  
Global Analysis ◽  
Marine Reserves ◽  
Relative Difference ◽  
Ecosystem Functions ◽  
Fish Biomass ◽  
High Compliance ◽  
Top Predators ◽  
Trade Offs

Coral reefs provide ecosystem goods and services for millions of people in the tropics, but reef conditions are declining worldwide. Effective solutions to the crisis facing coral reefs depend in part on understanding the context under which different types of conservation benefits can be maximized. Our global analysis of nearly 1,800 tropical reefs reveals how the intensity of human impacts in the surrounding seascape, measured as a function of human population size and accessibility to reefs (“gravity”), diminishes the effectiveness of marine reserves at sustaining reef fish biomass and the presence of top predators, even where compliance with reserve rules is high. Critically, fish biomass in high-compliance marine reserves located where human impacts were intensive tended to be less than a quarter that of reserves where human impacts were low. Similarly, the probability of encountering top predators on reefs with high human impacts was close to zero, even in high-compliance marine reserves. However, we find that the relative difference between openly fished sites and reserves (what we refer to as conservation gains) are highest for fish biomass (excluding predators) where human impacts are moderate and for top predators where human impacts are low. Our results illustrate critical ecological trade-offs in meeting key conservation objectives: reserves placed where there are moderate-to-high human impacts can provide substantial conservation gains for fish biomass, yet they are unlikely to support key ecosystem functions like higher-order predation, which is more prevalent in reserve locations with low human impacts.

Relationship Between Environmental Temperature and Yields of Subarctic and Temperate Zone Fish Species

1983 ◽  
Vol 40 (10) ◽  
pp. 1829-1837 ◽  
Author(s):  
David A. Schlesinger ◽  
Henry A. Regier
Keyword(s):  
Optimal Growth ◽  
Temperate Zone ◽  
Data Sets ◽  
Coregonus Clupeaformis ◽  
Influence Of Temperature On ◽  
Northern United States ◽  
Using Data ◽  
Curvilinear Relationships ◽  
Fish Yields

Fishes inhabiting subarctic and temperate zone lakes exhibit distinct optimal growth temperatures and temperature preferenda. However, within regional data sets, attempts to correlate fish yields with temperature variables have generally been unsuccessful. In our study, curvilinear relationships between "long-term mean annual air temperature" (TEMP) and sustained yields of three species were fitted using data from 23 intensively fished lakes in Canada and the northern United States. Optimum TEMP values for sustained yield were approximately −1.0, 1.5, and 2 °C, respectively, for lake whitefish (Coregonus clupeaformis), northern pike (Esox lucius), and walleye (Stizostedion vitreum vitreum). These differences suggest that the influence of temperature on sustained fish yields from subarctic and temperate zone lakes may, in the past, have been underestimated.

scholarly journals Measuring Sound at a Cold-Water Coral Reef to Assess the Impact of COVID-19 on Noise Pollution

2021 ◽  
Vol 8 ◽  
Author(s):  
Laurence H. De Clippele ◽  
Denise Risch
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Sea Level ◽  
Cold Water ◽  
Noise Pollution ◽  
Ecosystem Functions ◽  
Noise Levels ◽  
Level Height ◽  
Water Coral

This study compares the noise levels at the cold-water coral Tisler reef, before and after the closure of the border between Norway and Sweden, which occurred as a direct result of the COVID-19 pandemic. The Tisler reef is a marine protected area located under a ferry “highway” that connects Norway and Sweden. Cold-water coral reefs are recognised as being important hotspots of both biodiversity and biomass, they function as breeding and nursing grounds for commercially important fish and are essential in providing ecosystem functions. Whilst studies have shown that fishery, ocean warming, and acidification threaten them, the effects of noise pollution on cold-water coral reefs remains unstudied. To study the severity of noise pollution at the Tisler reef, a long-term acoustic recorder was deployed from 29 January 2020 until 26 May 2020. From 15 March COVID-19 lockdown measures stopped passenger vessel traffic between Norway and Sweden. This study found that the overall noise levels were significantly lower after border closure, due to reduced ferry traffic, wind speeds, and sea level height. When comparing the median hourly noise levels of before vs. after border closure, this study measured a significant reduction in the 63–125 Hz 1/3 octave band noise levels of 8.94 ± 0.88 (MAD) dB during the day (07:00:00–19:59:59) and 1.94 ± 0.11 (MAD) dB during the night (20:00:00–06:59:59). Since there was no ferry traffic during the night, the drop in noise levels at night was likely driven by seasonal changes, i.e., the reduction in wind speed and sea level height when transitioning from winter to spring. Taking into account this seasonal effect, it can be deduced that the COVID-19 border closure reduced the noise levels in the 63–125 Hz 1/3 octave bands at the Tisler reef by 7.0 ± 0.99 (MAD) dB during the day. While the contribution of, and changes in biological, weather-related and geophysical sound sources remain to be assessed in more detail, understanding the extent of anthropogenic noise pollution at the Tisler cold-water coral reef is critical to guide effective management to ensure the long-term health and conservation of its ecosystem functions.

scholarly journals Experimental reef communities persist under future ocean acidification and warming

2021 ◽  
Author(s):  
Christopher Jury ◽  
Keisha Bahr ◽  
Evan Barba ◽  
Russell Brainard ◽  
Annick Cros ◽  
...  
Keyword(s):  
Experimental Study ◽  
Species Richness ◽  
Coral Reef ◽  
Coral Reefs ◽  
Ocean Acidification ◽  
Community Composition ◽  
Functional State ◽  
Reef Communities ◽  
Paris Climate Agreement

Abstract Coral reefs are among the most sensitive ecosystems affected by ocean acidification and warming, and are predicted to shift from net accreting calcifier-dominated systems to net eroding algal-dominated systems over the coming decades. Here we present a long-term experimental study examining the responses of entire mesocosm coral reef communities to acidification (-0.2 pH units), warming (+ 2°C), and combined future ocean (-0.2 pH, + 2°C) treatments. We show that under future ocean conditions, net calcification rates declined yet remained positive, corals showed reduced abundance yet were not extirpated, and community composition shifted while species richness was maintained. Our results suggest that under Paris Climate Agreement targets, coral reefs could persist in an altered functional state rather than collapse.

scholarly journals INVESTIGATIONS ON MESOPHOTIC CORAL ECOSYSTEMS IN CUBA (1970-1973) AND MEXICO (1983-1984)

2018 ◽  
Vol 33 (2) ◽  
pp. 27
Author(s):  
Vassil Zlatarski
Keyword(s):  
Coral Reefs ◽  
Species Complex ◽  
Three Dimensional ◽  
Published Data ◽  
Two Dimensional ◽  
Mesophotic Coral Ecosystems ◽  
Trends Analysis ◽  
Collaborative Efforts ◽  
Existing Data

After a pioneering study of Jamaican coral reefs, the Cuban archipelago was the second to be surveyed by SCUBA for scleractinian corals and reef life to a depth of 90m, sampling all phenotypes.  Regrettably, the published data on the mesophotic coral ecosystems (MCEs) of Cuba, collected 1970 to 1973, have been ignored.  This is also true for the published data on the MCEs of the Mexican Yucatán Peninsula, collected 1983 to 1984.  These two investigations described immense areas exhibiting a rich continuum of coral life, from shallow reefs into MCEs without scleractinian faunal break, and no depth-specialists species complex.  Instead, a morphological changeover of three-dimensional corallum into two-dimensional corallum was observed and documented.  The existing data on the Cuban and Mexican MCEs (now 45 and 34 years old, respectively) present a unique opportunity for long-term status and ecosystem trends analysis.  MCEs require terminological clarification from collaborative efforts to effectively use the globally available data.Investigaciones sobre ecosistemas coralinos mesofóticos en Cuba (1970-1973) y México (1983-1984)RESUMEN. Después de un estudio pionero en arrecifes de Jamaica sobre corales escleratinios y vida arrecifal, el archipiélago cubano fue el segundo que se estudió mediante buceo SCUBA a profundidades de hasta 90m, incluyendo muestras de todos los fenotipos. Infortunadamente, los datos publicados sobre ecosistemas coralinos mesofóticos (ECM), recabados entre 1970 y 1973 han sido soslayados, al igual que los datos publicados sobre los ECM de la Península de Yucatán, México, recabados entre 1983 y 1984.  Ambas investigaciones describen áreas inmensas que exhiben un rico continuo de vida coralina, desde arrecifes someros hasta ECM sin ruptura en la fauna escleratinia y sin complejos de especies especialistas de profundidad. En vez de esto, se observó y documentó un reemplazamiento de formas tridimensionales de corales por formas bidimensionales.  La información existente sobre ECM cubanos y mexicanos con antigüedades de 45 y 34 años, respectivamente ofrecen una oportunidad única para realizar análisis sobre estatus a largo plazo y tendencias de ecosistema.  Los ECM requieren aclaración terminológica de esfuerzos de colaboración para utilizar efectivamente los datos disponibles globalmente.

scholarly journals Modern state of the reproductive potential of Black Sea sprat Sprattus sprattus phalericus (Risso, 1826) (Pisces: Clupeidae) in Crimean region and conditions for its formation

2019 ◽  
Vol 4 (4) ◽  
pp. 3-14
Author(s):  
G. V. Zuyev
Keyword(s):  
Black Sea ◽  
Average Length ◽  
Reproductive Potential ◽  
Danube River ◽  
The Black Sea ◽  
Total Catch ◽  
Sprattus Sprattus ◽  
The Absolute ◽  
Individual Fecundity

Black Sea sprat Sprattus sprattus phalericus (Risso, 1826) is one of the abundant species of fish in the Sea of Azov – Black Sea basin. Due to its large number sprat plays an extremely important role in the ecosystem of the sea, being an intermediate link between zooplankton and representatives of the highest trophic level – large predatory fish, dolphins, and birds. At the same time sprat is one of the important commercial fish in all the Black Sea countries, steadily being on the second place of catch volume in recent decades (after anchovy). The total catch reaches 100 thousand tons. Turkey and Ukraine are the main producing countries. Monitoring and forecast of biological state of sprat population with rising fishing intensity and climate changes are urgent tasks. The research subject of this article is the long-term (2000–2016) dynamics of biological (qualitative) parameters determining the population fecundity of Black Sea sprat in Crimean region, the current state of reproductive potential, and the conditions for its formation. The article is based on the results of own research. Parameters determining the population fecundity – the length-age structure of the spawning part population, the absolute individual fecundity, and the sex structure population (ratio between females and males) – were studied. In the long-term plan (in 2011–2016 compared with 2000–2004) the average length of spawning females decreased by 1.22 times (from 7.36 to 6.03 cm). It was accompanied by a decrease in the absolute individual fecundity by 2.39 times (from 13 625 to 5690 eggs). The numerical ratio between females and males decreased by 1.23 times (from 1.95 to 1.59). Simultaneously the sprat stock in the northern part of the Black Sea was reduced by more than 2.5 times (from > 500 thousand tons to < 200 thousand tons). As a result, the population fecundity of sprat in Crimean region decreased by more than 7 times (2.39 × 1.23 × 2.5). The conditions of sprat fishing in the northern part of the Black Sea (from the mouth of the Danube River to the Kerch Strait) were studied. They showed 2-fold decrease (from 251.9 thousand tons in 2000–2004 to 129.1 thousand tons in 2011–2016) in the total catch and more than 2.3-fold decrease (from 50.4 to 21.4 thousand tons) in average annual catch in this region. On the contrary, in the Crimean shelf the total catch at that time increased by 1.2 times (from 76.9 to 92.2 thousand tons), and its average annual value remained constant (15.4 thousand tons). While reducing the stock by 2.5 times, this means that the fishing pressure on the Crimean population increased 2.5 times. This fact suggests considering the factor of fishing as the main cause of its degradation. Validity of this version is confirmed by the fact of conjugacy (inverse connection) of interannual fluctuations between the catch and the length-age parameters of sprat in Crimean region in 2003–2013 previously found: catches over 15–16 thousand tons were accompanied by a next year decrease in the fish average length. Regulation of fishing is a necessary condition for preventing further degradation, for restoring and maintaining sustainable state of sprat population in Crimean region and its reproductive potential. The negative impact of natural (climatic and trophic) factors on the state of the population should be recognized as a secondary one. Local overfishing indicates indirectly the structuring of the commercial stock of Black Sea sprat, its division into a number of geographical aggregations (stock units), i. e. the presence of intraspecific differentiation.

Coral reef-associated bryozoans of Jamaica

Zootaxa ◽  
2021 ◽  
Vol 4988 (1) ◽  
pp. 1-218
Author(s):  
JUDITH E. WINSTON ◽  
JEREMY B.C. JACKSON
Keyword(s):  
Coral Reef ◽  
Coral Reefs ◽  
Rare Species ◽  
Ecological Study ◽  
Microscopy Study

As part of a long-term ecological study of the cryptic comunity of Jamaican coral reefs carried out by Jeremy B.C. Jackson and associates during the 1970s and early 1980s, collections were made of reef bryozoans found at 14 sites around the island. Space occupied by bryozoans on undercoral surfaces is dominated by relatively few species. However, during scanning electrone microscopy study and monograph preparation a diverse assortment of relatively rare species was discovered. Of the 132 species found, 56%, 74 species (70 cheilostomes and 4 cyclostomes) are new, as are one family (Inversiscaphidae) and 5 genera (Planospinella, Caribaria, Spirocoleopora, Gemellitheca, and Palliocella).  

scholarly journals Assessment of the Reproductive Health Status of Clarias Gariepinus (Burchell, 1822) in a River Impacted by Mercury from Clandestine Gold Mining: A Case Study of Bagoue River, Côte d’Ivoire

2020 ◽  
Vol 9 (1) ◽  
pp. 42
Author(s):  
Augustin KOUAME N’ Guessan ◽  
Rodrigue Orobiyi Edéya PELEBE ◽  
Koffi Charles BOUSSOU ◽  
Valentin N’DOUBA
Keyword(s):  
Reproductive Health ◽  
Gold Mining ◽  
Clarias Gariepinus ◽  
Reproductive Capacity ◽  
Histological Assessment ◽  
Circulatory Disturbance ◽  
Target Fish ◽  
Regressive Changes ◽  
Liver Tissues

Pollution of aquatic ecosystems often results in adverse environmental disturbances, including individual and/or sub-individual changes in fish. The aim of the present study was to examine possible reproductive health effects in male and female, based on a histological assessment of Clarias gariepinus sampled in Bagoue River impacted by mercury from the artisanal gold mining. Fish were collected between August 2018 and April 2019 during two seasons from four stations differently impacted. A histological assessment was done on three target fish organs (liver, ovary and testis). Water and sediment samples were analysed for total mercury (T-Hg) concentration. Histological alterations were semi-quantitatively assessed, and the results were classified according to the severity of the histological response identified. Microscopic assessment revealed alterations of the gonads and liver tissues. A higher incidence of reaction pattern (Regressive changes, Inflammation and Circulatory disturbance) was found in liver tissues than in gonads tissues (Regressive changes). T-Hg levels were higher upstream than downstream in ovaries and testis tissues. Paradoxically, the lesions observed in these organs were more pronounced downstream than those found in fish from upstream during rainy season. According to total index, the organs examined downstream suffered severe damage unlike upstream sites. Also, comparison of degree of alteration between testes and ovaries indicates a greater impact of ovarian structures especially on downstream sites. The effect of anthropogenic impact appears to be visible downstream as the concentration of chemical pollutants and exposure time determine the severity of the damage. Alterations in ovarian follicles, spermatogenic cells and liver tissues may reflect damage to the process of gametogenesis, which may reduce the reproductive capacity of individuals over the long term.

Long-term ecological changes in fishes and macro-invertebrates in the world's warmest coral reefs

2021 ◽  
Vol 750 ◽  
pp. 142254
Author(s):  
Yu-Jia Lin ◽  
Lotfi Rabaoui ◽  
Abdullajid Usama Basali ◽  
Maclopez Lopez ◽  
Reynaldo Lindo ◽  
...  
Keyword(s):  
Coral Reefs ◽  
Ecological Changes

scholarly journals Simulations of Long-Term Community Dynamics in Coral Reefs - How Perturbations Shape Trajectories

2012 ◽  
Vol 8 (11) ◽  
pp. e1002791 ◽  
Author(s):  
Andreas Kubicek ◽  
Christopher Muhando ◽  
Hauke Reuter
Keyword(s):  
Coral Reefs ◽  
Community Dynamics
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