scholarly journals Variation of Density and Biomass of the Ichthyofauna Associated to Soft Bottoms of a Western Coastal Lagoon of B.C.S., Mexico

2021 ◽  
Vol 11 (04) ◽  
pp. 169-186
Author(s):  
Bruma Rachel Castillo Rosas ◽  
Emelio Barjau González ◽  
Juan Manuel López Viva ◽  
José Ángel Armenta Quintana ◽  
Javier Aguilar Parra ◽  
...  
Keyword(s):  
Coastal Lagoon ◽  
Soft Bottoms ◽  
Density And Biomass

scholarly journals Variation of the Fish Community Associated with Soft Bottoms in a Coastal Lagoon on the Pacific Side of B.C.S, Mexico

2017 ◽  
Author(s):  
Felipe Munoz-Felix ◽  
Emelio Barjau-Gonzalez ◽  
Abril Karin Romo-Pinera ◽  
Juan Manuel Lopez-Vivas
Keyword(s):  
Coastal Lagoon ◽  
Fish Community ◽  
The Pacific ◽  
Pacific Side ◽  
Soft Bottoms

scholarly journals Space-time variations of megazoobenthos subject to natural and anthropogenic impacts in two Cuban bays: evidence of recovery?

2021 ◽  
Vol 49 (1) ◽  
pp. 97-109
Author(s):  
Alexander Lopeztegui-Castillo ◽  
Norberto Capetillo-Piñar ◽  
Abel Betanzos-Vega ◽  
Beatriz Martínez-Daranas ◽  
Diana Martínez-Coello ◽  
...  
Keyword(s):  
Anthropogenic Impacts ◽  
Benthic Fauna ◽  
Progressive Increase ◽  
Bottom Trawl ◽  
Total Biomass ◽  
Total Density ◽  
Buena Vista ◽  
Soft Bottoms ◽  
Density And Biomass ◽  
Trawl Fisheries

The spatiotemporal variations of megazoobenthos on soft bottoms in Buena Vista (BV) and San Juan de Los Remedios (SJR) bays, Cuba, were assessed to infer the effects of the elimination of bottom trawl fisheries and the creation of protected areas. Data were collected at 11 sites in 2010-2013 (six routines and five exploratories) and 11 sites in 2014-2017 (four routines and seven exploratories). Samples were obtained by dredging. Mollusks were the most frequent and diverse group, followed by echinoderms and crustaceans. Total density (7.60 ind m-2) and biomass (15.82 g m-2) of the benthic community were highest in SJR in 2015. Although total biomass was lower at BV (t = 2.21; P = 0.032), there were no significant differences in density between bays (t = 0.77; P = 0.444). The site with a lower total density and biomass was located at BV. There were no differences between years except at one site, where density increased between 2010 and 2017. Total density and biomass were not significantly different inside and outside of the Zone Under Special Regime of Use and Protection (ZUSRUP) at the beginning of the sampled period. However, both density and biomass were significantly higher within the ZUSRUP at the end (2017), which suggests this protected area’s effectivity. The progressive increase in density at one site and greater density and biomass values at SJR, where bottom trawl fisheries were more intensive, suggest eliminating bottom trawl nets may have contributed to the benthic fauna recovery.

Effects of marine reserves on predator-prey interactions in central California kelp forests

2020 ◽  
Vol 655 ◽  
pp. 139-155
Author(s):  
DC Yates ◽  
SI Lonhart ◽  
SL Hamilton
Keyword(s):  
Species Interactions ◽  
Size Structure ◽  
Marine Reserves ◽  
Mortality Rates ◽  
Kelp Forests ◽  
Negative Effects ◽  
Central California ◽  
Invertebrate Predators ◽  
Predatory Fishes ◽  
Density And Biomass

Marine reserves are often designed to increase density, biomass, size structure, and biodiversity by prohibiting extractive activities. However, the recovery of predators following the establishment of marine reserves and the consequent cessation of fishing may have indirect negative effects on prey populations by increasing prey mortality. We coupled field surveys with empirical predation assays (i.e. tethering experiments) inside and outside of 3 no-take marine reserves in kelp forests along the central California coast to quantify the strength of interactions between predatory fishes and their crustacean prey. Results indicated elevated densities and biomass of invertebrate predators inside marine reserves compared to nearby fished sites, but no significant differences in prey densities. The increased abundance of predators inside marine reserves translated to a significant increase in mortality of 2 species of decapod crustaceans, the dock shrimp Pandalus danae and the cryptic kelp crab Pugettia richii, in tethering experiments. Shrimp mortality rates were 4.6 times greater, while crab mortality rates were 7 times greater inside reserves. For both prey species, the time to 50% mortality was negatively associated with the density and biomass of invertebrate predators (i.e. higher mortality rates where predators were more abundant). Video analyses indicated that macro-invertivore fishes arrived 2 times faster to tethering arrays at sites inside marine reserves and began attacking tethered prey more rapidly. The results indicate that marine reserves can have direct and indirect effects on predators and their prey, respectively, and highlight the importance of considering species interactions in making management decisions.

Conservation and Restoration of Grasslands

2018 ◽  
Author(s):  
Brian J. Wilsey
Keyword(s):  
Community Assembly ◽  
Woody Plants ◽  
Woody Plant ◽  
Priority Effects ◽  
Woody Plant Encroachment ◽  
Humpty Dumpty ◽  
Alternate States ◽  
Density And Biomass ◽  
Acid Test ◽  
Stocking Rates

Conservation programs alter herbivore stocking rates and find and protect the remaining areas that have not been plowed or converted to crops. Restoration is an ‘Acid Test’ for ecology. If we fully understand how grassland systems function and assemble after disturbance, then it should be easy to restore them after they have been degraded or destroyed. Alternatively, the idea that restorations will not be equivalent to remnants has been termed the ‘Humpty Dumpty’ hypothesis—once lost, it cannot be put back together again. Community assembly may follow rules, and if these rules are uncovered, then we may be able to accurately predict final species composition after assembly. Priority effects are sometimes found depending on species arrival orders, and they can result in alternate states. Woody plant encroachment is the increase in density and biomass of woody plants, and it is strongly affecting grassland C and water cycles.

Suppression of Weed Occurrence in a Five-year Corn-earthworm Coculture System

Weed Science ◽  
2020 ◽  
pp. 1-23
Author(s):  
Tao Li ◽  
Jiequn Fan ◽  
Zhenguan Qian ◽  
Guohui Yuan ◽  
Dandan Meng ◽  
...  
Keyword(s):  
Weed Species ◽  
Ecological Benefits ◽  
Economic Output ◽  
Green Foxtail ◽  
Weed Diversity ◽  
The Mean ◽  
Common Purslane ◽  
Species Specific ◽  
Density And Biomass ◽  
Successive Experiment

Abstract The use of a corn-earthworm coculture (CE) system is an eco-agricultural technology that has been gradually extended due to its high economic output and diverse ecological benefits for urban agriculture in China. However, the effect of CE on weed occurrence has received little attention. A five-year successive experiment (2015 to 2019) was conducted to compare weed occurrence in CE and a corn (Zea mays L.) monoculture (CM). The results show that CE significantly decreased weed diversity, the dominance index, total weed density and biomass, but increased the weed evenness index. The five-year mean number of weed species per plot was 8.4 in CE and 10.7 in CM. Compared to those in CM, the five-year mean density and biomass of total weeds in CE decreased by 59.2% and 66.6%, respectively. The effect of CE on weed occurrence was species specific. The mean density of large crabgrass [Digitaria sanguinalis (L.) Scop.], green foxtail [Setaria viridis (L.) Beauv.], goosegrass [Eleusine indica (L.) Gaertn.], and common purslane (Portulaca oleracea L.) in CE decreased by 94.5, 78.1, 75.0, and 45.8%, whereas the mean biomass decreased by 96.2, 80.8, 76.9, and 41.4%, respectively. Our study suggests that the use of CE could suppress weed occurrence and reduce herbicide inputs in agriculture.

scholarly journals Boat Noise and Black Drum Vocalizations in Mar Chiquita Coastal Lagoon (Argentina)

2021 ◽  
Vol 9 (1) ◽  
pp. 44
Author(s):  
Maria Ceraulo ◽  
María Paz Sal Moyano ◽  
Fernando Jose Hidalgo ◽  
María Cielo Bazterrica ◽  
Salvatore Mazzola ◽  
...  
Keyword(s):  
Fish Species ◽  
Coastal Lagoon ◽  
Acoustic Method ◽  
Potential Effect ◽  
Reproductive Period ◽  
Anthropogenic Noise ◽  
Marine Biota ◽  
Call Rate ◽  
Noise Frequency ◽  
Passive Acoustic

Human-generated underwater noise and its effect on marine biota is recognized as an important issue. Boat noise can affect the communication success of fish species that use sounds for spawning purposes. During the reproductive period, males of the black drum Pogonias spp. produce calls ranging from 90 Hz to 300 Hz. In the Mar Chiquita coastal lagoon (Buenos Aires, Argentina), Pogonias courbina is one of the primary fishing species. Although no regulation is directly applied to protect it, a ban protects the reproductive period of other fish species during weekdays. Here, we investigated the potential effect of boat noise on P. courbina vocalizations through a passive acoustic method. Acoustic data were collected, and P. courbina calls were identified and counted. The files with boat noise passages were categorized into classes according to their noise frequency range (A = below 700 Hz, B = over 700 Hz, and C = below and above 700 Hz). The fish call rate was lower in files where boat noise overlapped the fish call frequency (Classes A and C). Only boat noise from Class C was significantly reduced during days with the active fishing ban. These results suggest that anthropogenic noise may affect the P. courbina call rate and underline the importance of including the evaluation of anthropogenic noise in the current management of the area.

Non-conservative removal of dissolved rhenium from a coastal lagoon: Clay adsorption versus biological uptake

2021 ◽  
pp. 120378
Author(s):  
Mohd Danish ◽  
Gyana Ranjan Tripathy ◽  
Sirsha Mitra ◽  
Rakesh Kumar Rout ◽  
Shubhangi Raskar
Keyword(s):  
Coastal Lagoon ◽  
Biological Uptake
Sign in / Sign up

Export Citation Format

Share Document