Effect of Vegetable Growth on Content and Composition of Antibiotics in Litopenaeus vannamei Pond Sediments in Crop/Aquacultural Rotation Process

Photodegradation remains the major pathway of antibiotic removal in natural ponds. This study introduced a new method of growing vegetables on the bottom substrate of shrimp ponds to improve sediment quality. The aim of the study was to investigate the effect of vegetable planting on the photodegradation of antibiotics. This study characterized antibiotic levels in the pond sediment during this phytoremediation process and investigated the antibiotic content and composition of the sediment with and without crop rotation (traditional control), as well as the shrimp yields. The results showed that total antibiotics (e.g., trimethoprim, oxytetracycline, and norfloxacin) in the sediment of all aquaculture ponds continuously decreased from 44.78 ± 4.07 μg/kg to 18.80 ± 2.26 μg/kg in the crop rotation pond. The total amount of antibiotics consistently decreased in all ponds, and the rate of decline did not greatly differ. However, oxytetracycline in the crop rotation pond decreased faster than in the control pond, presumably because the growing vegetables altered the sediment and microbial-community characteristics that promoted oxytetracycline degradation. In the following year, there was little difference in the levels of norfloxacin or oxytetracycline between the two ponds. An increase in trimethoprim in the control pond was much higher than in the crop-growing sediment. It was indicated that the system remediated the shrimp pond ecosystem as well as providing the possibility of increasing profits by planting vegetables in the winter idle period of shrimp ponds.

The natural factors and anthropogenic stressors influence on Chironomidae communities of two north-African wadis

Mediterranean streams reveal high biodiversity and play a crucial role for local populations. North African wadis are less known than European streams. Hence, there is a need to explore factors influencing their communities. Chironomid assemblages of the Seybouse and El Kebir-west wadis, located in Algeria, were surveyed between July 2016 and July 2017. Among 28,045 collected larvae, 51 taxa were identified. The obtained results indicate that wadis saprobity, conductivity and pH vary seasonally. Air temperature and precipitation affect wadis differently in summer and winter. Two gradients driven by altitude define the river continuum: (1) the bottom substrate, from coarse to fine, and water quality, (2) the variety of meso-habitats from natural to anthropogenic. El Kebir-west, as a natural wadi, has unified communities throughout all its length. Communities of Seybouse vary due to the fact that this larger river is strongly influenced by human activity. Water management in Algeria should focus equally on water quality and natural habitats treatment.

Substrate-dependent fish have shifted less in distribution under climate change

Analyses of the impacts of climate change on fish species have primarily considered dynamic oceanographic variables that are the output of predictive models, yet fish species distributions are determined by much more than just variables such as ocean temperature. Functionally diverse species are differentially influenced by oceanographic as well as physiographic variables such as bottom substrate, thereby influencing their ability to shift distributions. Here, we show that fish species distributions that are more associated with bottom substrate than other dynamic environmental variables have shifted significantly less over the last 30 years than species whose distributions are associated with bottom salinity. Correspondingly, species whose distributions are primarily determined by bottom temperature or ocean salinity have shifted their mean centroid and southern and northern range boundaries significantly more than species whose distributions are determined by substrate or depth. The influence of oceanographic versus static variables differs by species functional group, as benthic species distributions are more associated with substrate and they have shifted significantly less than pelagic species whose distributions are primarily associated with ocean temperatures. In conclusion, benthic fish, that are more influenced by substrate, may prove much less likely to shift distributions under future climate change.

Surface Stabilized Topological Solitons in Nematic Liquid Crystals

Photo-alignment is a versatile tool to pattern the alignment at the confining substrates in a liquid crystal (LC) cell. Arbitrary alignment patterns can be created by using projection with a spatial light modulator (SLM) for the illumination. We demonstrate that a careful design of the alignment patterns allows the stabilization of topological solitons in nematic liquid crystal (NLC) cells, without the need for chirality or strong confinement. The created LC configurations are stabilized by the anchoring conditions imposed at the substrates. The photo-aligned background at both substrates is uniformly planar aligned, and ring-shaped regions with a 180° azimuthal rotation are patterned with an opposite sense of rotation at the top and bottom substrate. A disclination-free structure containing a closed ring of vertically oriented directors is formed when the patterned rings at the top and bottom substrate overlap. Thanks to the topological stability, a vertical director orientation in the bulk is observed even when the centra of both patterned rings are shifted over relatively large distances. The combination of numerical simulations with experimental measurements allows identification of the 3D director configuration in the bulk. A finite element (FE) Q-tensor simulation model is applied to find the equilibrium director configuration and optical simulations are used to confirm the correspondence with experimental microscopy measurements. The created LC configurations offer opportunities in the field of optical devices, light guiding and switching, particle trapping and studies of topological LC structures.

Simpanan Karbon Padang Lamun di Kawasan Pantai Nusa Lembongan, Klungkung, Bali

The seagrass ecosystem has great potential in absorbing of CO2 concentration in atmosphere, results of the process photosynthesis will be stored in form of biomass during seagrass still alive. The research purpose was to know carbon storage from the seagrass ecosystem at the top substrate (leaves) and bottom substrates (rhizome and roots) in Nusa Lembongan coastal area, Bali. The research location is divided into three stations with 27 points. Carbon stock was analyzed by using invasion method consisting of calculating the value of ash content, organic matter content and carbon content. The results found three seagrass species in the Nusa Lembongan coastal area: Thalassia hemprichii, Cymodocea rotundata and Enhalus acoroides. The most dominant spesies is the Thalassia hemprichii. The carbon stored at the top substrate (leaf) is 21.08 gC/m2 and the bottom substrates (rhizome and root) are 52.67 gC/m2. The total estimated carbon deposits in the Nusa Lembongan coastal area is 65.98 tonnes with carbon deposits in the bottom substrate are larger than the top substrate, which is 71% or 47.12 tons on the bottom substrate while 29% or 18.86 tons on the top substrate.

Relationship Between Length-Weight, Condition Factor and Diversity Sex of Blood Cckle in Sedati, Sidoarjo, East Java

Sidoarjo regency is a district that has marine waters and has the potential to capture the resources of the shell. It is very influential in the livelihoods of the community, especially people sedati, sidoarjo. One of the resources in Sedati is the blood cockle (Anadara sp.), These shells include bivalves that live on the bottom substrate with muddy sand conditions. Catching of the shell has been done in hereditary by Sedati community. This catching activity can have an adverse effect if the capture of blood cockle (Anadara sp.) Is not controlled in an environmentally friendly and sustainable manner and the pollution of the marine environment in Sedati also has an effect on the quality of the Sedati sea waters. This study examines the growth aspect of long-range distribution, long relationship of weight, condition factor and sex ratio of blood cockle (Anadara sp.) in sedati waters, Sidoarjo, East Java.

Diet and foraging behavior of Ageneiosus inermis (Teleostei, Auchenipteridae)

Ageneiosus inermis is the largest species of the family Auchenipteridae (Siluriformes) and has a primarily piscivorous diet, although no comprehensive data are available on the habitat use of this species. Given this, the present study describes the diet of A. inermis, and provides inferences on its habitat use, based on the known behavior of its prey species. We analyzed the stomach contents of 14 specimens collected in the middle of Xingu River in the Brazilian state of Pará, which we complemented with data on 47 other specimens obtained from two published studies. Most of the ingested items were fish associated with the bottom substrate and riverbanks. Although A. inermis is considered a pelagic species, we conclude it forages by exploring the river’s bottom and margins. Furthermore, as A. inermis is presumed to be diurnal, we assume that it does not pursue its prey actively, given that most of the prey species are nocturnal, but rather searches actively during the daytime for prey hidden in the bottom substrate. This hypothesis on the feeding strategy of A. inermis can only be confirmed by underwater observations, either in the wild or under captive conditions.