scholarly journals Is this rock pool suitable habitat? Fish diversity in intertidal rock pools of El Zonte, El Salvador

2020 ◽  
Vol 91 (1) ◽  
pp. 913099
Author(s):  
Saúl González-Murcia ◽  
Sandra Erdmann ◽  
Raquel Alvarado-Larios
Keyword(s):  
El Salvador ◽  
Fish Diversity ◽  
Suitable Habitat ◽  
Rock Pools ◽  
Rock Pool

Corrigendum to: Size, depth and position affect the diversity and structure of rock pool communities in an urban estuary

2019 ◽  
Vol 70 (7) ◽  
pp. 1045
Author(s):  
Nina Schaefer ◽  
Katherine A. Dafforn ◽  
Emma L. Johnston ◽  
Mariana Mayer-Pinto
Keyword(s):  
Species Diversity ◽  
Environmental Conditions ◽  
Outer Zone ◽  
Ecological Niches ◽  
Rocky Shores ◽  
Rock Pools ◽  
Rock Pool ◽  
Taxa Richness ◽  
Urban Estuary ◽  
Sydney Harbour

Rock pools provide a range of ecological niches that can support diverse assemblages on rocky shores. As intertidal shores are increasingly lost to developments, understanding the drivers of diversity in rock pools is important for the conservation and construction of these key habitats. In this study we investigated relationships between physical characteristics of rock pools and their biota in an urban estuary. We sampled the biota every 6 weeks for 1 year at sites in the inner and outer zones of Sydney Harbour. In the well-flushed and exposed outer zone, sessile and mobile taxa richness was positively related to rock pool width, whereas only mobile taxa richness was related to depth and volume. In the more urbanised and less exposed inner zone, mobile taxa richness was positively related to rock pool width and volume. In both zones, sessile taxa richness decreased with increasing height on shore. Our results suggest that the biodiversity of intertidal rock pools varies depending on their position in Sydney Harbour and the available species pool. Therefore, restoration efforts should consider rock pool size parameters and local environmental conditions, including location, so designs can be optimised to maximise species diversity in these pools.

scholarly journals Water quality and fish diversity of Federal University of Agriculture Abeokuta reservoir

2021 ◽  
Vol 39 (2) ◽  
pp. 150-155
Author(s):  
F. I. Adeosun ◽  
W. O. Abdul ◽  
A. A. Akinyemi ◽  
A. O. Agbon ◽  
O. C. Odebiyi
Keyword(s):  
Water Quality ◽  
Fish Species ◽  
Clarias Gariepinus ◽  
Quality Parameters ◽  
Fish Diversity ◽  
Suitable Habitat ◽  
Reservoir Water ◽  
Reservoir Water Level ◽  
Fish Yield ◽  
Ogun State

Federal University of Agriculture reservoir is one of the recently constructed in Abeokuta, Ogun state, Nigeria, therefore the need to assess the water quality, fish diversity and catch assessment of this new water body. Data on fish species were collected on a forthnight basis using multi-stage gillnet sampling techniques for four months (September- December, 2011). Three sampling stations were randomly selected from the entire reservoir. A variety of sampling methods were used at each site in order to reach every fish species. At the river channel and the floodplain sites, traps, cast nets (2.55cm mesh), seine nets (2.55 x 2 cm mesh), monofilament nylon gillnets (15.55 cm mesh), and hook and line were employed. Efforts were made in order to catch fish species in large abundance. Some sampled fish (dead) were collected and placed in cool boxes and examined within 18 hours of capture. Others were preserved in 15% formalin and stored for later examination. A total of 863 fish specimens were caught during the study period. These were identified and classified into 5 species belonging to 3 families. The percentage species composition of the harvest by numbers and weight for all fish species that contributed more than 1% in all the stations combined, were computed. Study of the physico-chemical parameter such as dissolved oxygen ranged from 5.03 to 7.19mg/l; 26 to 280C temperature; 64.8 to 148ppm alkaline; pH 6.67-6.90; 32.5 to 53.5m transparent; 8.86 to 13.72mg/l nitrate; 0.58 to 0.64mg/l phosphate; 0.024 to 0.069 o/oo saline; 103-270cm deep. pH and water temperature serve as variables since the fluctuation of one affects the values of others. The water quality parameters were favourable for fish production. The gillnet fisheries indicated that different mesh sizes of experimental gillnets were sensitive to different fish species. 67.2mm, 78.4mm and 112mm, mesh sizes were efficient in catching Clarias gariepinus, Barbus occidentalis and the Cichlids respectively. The study has shown that middle water was the most suitable habitat for fish in the reservoir. Water level and temperature were observed to guarantee high fish yield in the reservoir.

Size, depth and position affect the diversity and structure of rock pool communities in an urban estuary

2019 ◽  
Vol 70 (7) ◽  
pp. 1034 ◽  
Author(s):  
Nina Schaefer ◽  
Katherine A. Dafforn ◽  
Emma L. Johnston ◽  
Mariana Mayer-Pinto
Keyword(s):  
Species Diversity ◽  
Environmental Conditions ◽  
Outer Zone ◽  
Ecological Niches ◽  
Rocky Shores ◽  
Rock Pools ◽  
Rock Pool ◽  
Taxa Richness ◽  
Urban Estuary ◽  
Sydney Harbour

Rock pools provide a range of ecological niches that can support diverse assemblages on rocky shores. As intertidal shores are increasingly lost to developments, understanding the drivers of diversity in rock pools is important for the conservation and construction of these key habitats. In this study we investigated relationships between physical characteristics of rock pools and their biota in an urban estuary. We sampled the biota every 6 weeks for 1 year at sites in the inner and outer zones of Sydney Harbour. In the well-flushed and exposed outer zone, sessile and mobile taxa richness was positively related to rock pool width, whereas only mobile taxa richness was related to depth and volume. In the more urbanised and less exposed inner zone, mobile taxa richness was positively related to rock pool width and volume. In both zones, sessile taxa richness decreased with increasing height on shore. Our results suggest that the biodiversity of intertidal rock pools varies depending on their position in Sydney Harbour and the available species pool. Therefore, restoration efforts should consider rock pool size parameters and local environmental conditions, including location, so designs can be optimised to maximise species diversity in these pools.

Eggs, larvae, and spawning in Melarapha cincta (Quoy & Gaimard) and M. oliveri Finlay (Littorinidae, Gastropoda)

1971 ◽  
Vol 22 (2) ◽  
pp. 79 ◽  
Author(s):  
MC Pilkington
Keyword(s):  
New Zealand ◽  
Breeding Season ◽  
Room Temperature ◽  
Mixed Population ◽  
Rock Pools ◽  
Rock Pool ◽  
Side View ◽  
Egg Capsules ◽  
Veliger Stage ◽  
Early Veliger

Both the New Zealand species of Melarapha, M. cincta and M. oliveri, laid minute planktonic egg capsules, of the "Drum" type, in the laboratory. Capsules were similar in the two species, but could be distinguished in side view by shape. Eggs developed rapidly, hatching at an early veliger stage in 3-4 days at room temperature. Attempts to rear these very small larvae were not successful, but later veligers, taken from plankton hauls, were reared through metamorphosis and identified as Melarapha. Veliger stages are drawn and described and the length of planktonic life assessed as 1-2 months. The two species are indistinguishable after hatching until many months after metamorphosis when the adult coloration of the shell is developed. Spawning was studied at Portobello in a mixed population of M. cincta and M. Oliveri extending from high HWS to low HWS. The breeding season was from November to March. Spawning, in animals associated with rock pools, occurred intermittently and not particularly during spring tides. The presence of egg capsules of both species in rock pool samples was associated ( χ² tests) with a rock pool salinity of 33-36‰ and with the occurrence of rough weather.

scholarly journals Fish Diversity at Pancheshwar Multipurpose Project Area in Mahakali River

2013 ◽  
Vol 13 (2) ◽  
pp. 225-230
Author(s):  
Tej B Saund ◽  
Jham B Thapa ◽  
Harish P Bhatt
Keyword(s):  
Water Quality ◽  
Fish Species ◽  
Quality Parameters ◽  
Fish Diversity ◽  
Suitable Habitat ◽  
Project Area ◽  
Baseline Information ◽  
Total Fish ◽  
Fish Species Composition ◽  
Study Sites

A study was carried out to prepare a baseline information on water quality and freshwater fish diversity at Pancheshwar Multipurpose Project area in Mahakali river. The study was conducted in autumn (October 2008) and summer (June 2009). A total of 24 fish species belonging to 3 orders, 4 families and 13 genera were recorded during the investigation period. Cypriniformes was the most dominant order accounting 75% of total fish species. Siluriformes and Synbranchiformes accounted for 21% and 4% of fish species composition respectively. Spawning and rearing areas in study sites were evenly distributed providing a suitable habitat for both cold and warm water fish species. The water quality parameters, i.e., water temperature (20.50-22.63 0C), DO (8.58-11.85 mg/l) and pH (6.93-7.20) were found within the suitable range supporting diverse fish species. Nepal Journal of Science and Technology Vol. 13, No. 2 (2012) 225-230 DOI: http://dx.doi.org/10.3126/njst.v13i2.7741

Ideas and Leaders in Contentious Politics: One Parish Priest in El Salvador's Popular Movement

2014 ◽  
Vol 38 (01) ◽  
pp. 76-101
Author(s):  
PETER M. SANCHEZ
Keyword(s):  
Collective Action ◽  
El Salvador ◽  
Liberation Theology ◽  
Contentious Politics ◽  
Religious Leaders ◽  
Political Movement ◽  
Parish Priest ◽  
Historical Moment ◽  
Resource Mobilisation ◽  
The Church

AbstractThis paper examines the actions of one Salvadorean priest – Padre David Rodríguez – in one parish – Tecoluca – to underscore the importance of religious leadership in the rise of El Salvador's contentious political movement that began in the early 1970s, when the guerrilla organisations were only just beginning to develop. Catholic leaders became engaged in promoting contentious politics, however, only after the Church had experienced an ideological conversion, commonly referred to as liberation theology. A focus on one priest, in one parish, allows for generalisation, since scores of priests, nuns and lay workers in El Salvador followed the same injustice frame and tactics that generated extensive political mobilisation throughout the country. While structural conditions, collective action and resource mobilisation are undoubtedly necessary, the case of religious leaders in El Salvador suggests that ideas and leadership are of vital importance for the rise of contentious politics at a particular historical moment.

The Genesis and Internal Dynamics of El Salvador's People's Revolutionary Army, 1970–1976

2014 ◽  
Vol 38 (01) ◽  
pp. 102-129
Author(s):  
ALBERTO MARTÍN ÁLVAREZ ◽  
EUDALD CORTINA ORERO
Keyword(s):  
Latin America ◽  
El Salvador ◽  
Early Years ◽  
Left Wing ◽  
Internal Dynamics ◽  
Internal Coherence ◽  
The 1960S

AbstractUsing interviews with former militants and previously unpublished documents, this article traces the genesis and internal dynamics of the Ejército Revolucionario del Pueblo (People's Revolutionary Army, ERP) in El Salvador during the early years of its existence (1970–6). This period was marked by the inability of the ERP to maintain internal coherence or any consensus on revolutionary strategy, which led to a series of splits and internal fights over control of the organisation. The evidence marshalled in this case study sheds new light on the origins of the armed Salvadorean Left and thus contributes to a wider understanding of the processes of formation and internal dynamics of armed left-wing groups that emerged from the 1960s onwards in Latin America.

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