Physical disturbance and subtidal habitat structure on open rocky coasts: Effects of wave exposure, extent and intensity

2008 ◽  
Vol 59 (4) ◽  
pp. 237-248 ◽  
Author(s):  
Thomas Wernberg ◽  
Sean D. Connell
Keyword(s):  
Habitat Structure ◽  
Wave Exposure ◽  
Physical Disturbance ◽  
Subtidal Habitat ◽  
Rocky Coasts

Recent advances in understanding the environmental footprint of trawling on the seabed

2019 ◽  
Vol 97 (9) ◽  
pp. 755-762 ◽  
Author(s):  
Michel J. Kaiser
Keyword(s):  
Habitat Structure ◽  
Meta Analysis ◽  
Environmental Footprint ◽  
Physical Disturbance ◽  
Carbon Footprints ◽  
Modelling Framework ◽  
Management Measures ◽  
Highly Sensitive ◽  
Different Types ◽  
Fishing Impacts

Bottom trawling accounts for nearly a quarter of wild-capture seafood production, but it is associated with physical disturbance of the seabed leading to changes in benthic abundance, habitat structure, and biogeochemical processes. Understanding the processes of benthic depletion and recovery in relation to different types of fishing gears, and in different seabed types, is an important pre-requisite to inform appropriate management measures to limit or reduce the effects of trawling on the seabed. The combined approaches of meta-analysis and modelling that link fishing-gear penetration of the seabed to benthic depletion, and recovery to taxon longevity, have enabled the development of a modelling framework to estimate relative benthic status in areas subject to trawling. Such estimations are highly sensitive to the spatial resolution at which fishing footprint (trawl track) data are aggregated, and this leads to overinflated estimates of fishing impacts on benthos when coarse-level aggregation is applied. These approaches present a framework into which other “sustainability” criteria can be added, e.g., the consideration of carbon footprints of fishing activities.

scholarly journals Spatial variation in the structure of overwintering, remnant Saccorhiza polyschides sporophytes and their associated assemblages

2021 ◽  
pp. 1-10
Author(s):  
Nora Salland ◽  
Dan Smale
Keyword(s):  
Habitat Structure ◽  
Wave Exposure ◽  
Marine Ecology ◽  
Taxon Richness ◽  
Faunal Assemblages ◽  
Faunal Abundance ◽  
Saccorhiza Polyschides ◽  
Fundamental Goal ◽  
Internal Volume ◽  
The Uk

Abstract Understanding the structure and richness of natural communities is a fundamental goal of marine ecology, and foundation species such as large macroalgae have a disproportionate role in structuring biodiversity. However, high-resolution information on assemblages associated with macroalgae is lacking for many species and regions. Saccorhiza polyschides is a warm-temperate kelp with a relatively short lifespan (12–18 months), large thallus and bulbous holdfast offering habitat for diverse assemblages. In the UK, S. polyschides populations are thought to have proliferated recently. Here, we quantified the density and habitat structure provided by S. polyschides along a gradient of wave exposure within Plymouth Sound, and examined the composition and diversity of associated faunal assemblages. Density varied significantly between sites but not by wave exposure, while biometric measurements were generally highly variable. Senescing holdfasts from sporophytes offered valuable habitat, with high abundance and richness of associated assemblages, although these varied markedly between sporophytes and sites. Faunal abundance, taxon richness and diversity were significantly higher at fully exposed sites than at moderately exposed sites. Internal volume of holdfasts was positively correlated with faunal abundance and taxon richness. We recorded more than 27 distinct taxa and up to ~600 individuals within a single holdfast. Taxa included three fish species, including a novel observation of the pipefish Nerophis lumbriciformis. Further work is needed to examine seasonality in habitat structure and associated diversity patterns but our study demonstrates that even remnant holdfasts from decaying sporophytes represent a valuable microhabitat that may provide shelter, protection and food during winter.

Seaweed traits linked to wave exposure determine predator avoidance

2013 ◽  
Vol 483 ◽  
pp. 143-151 ◽  
Author(s):  
JD Long ◽  
L Porturas ◽  
E Jones ◽  
C Kwan ◽  
GC Trussell
Keyword(s):  
Predator Avoidance ◽  
Wave Exposure

Pengaruh Variasi Waktu Paparan Gelombang Ultrasonik dalam Mengurangi Jumlah Bakteri coliform pada Sampel Air Sungai Kahayan

2020 ◽  
Vol 4 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Neny Kurniawati, Kerelius, Sunariyati ◽  
Luqman Hakim, Dyah Ayu Pramoda Wardani, Widya Krestina ◽  
Dwi Tyas Setiawan, Ferry Purwanto, Diah K. Fatmala
Keyword(s):  
Water Treatment ◽  
River Water ◽  
Ultrasonic Wave ◽  
Exposure Time ◽  
Water Samples ◽  
Sampling Technique ◽  
Wave Exposure ◽  
Test Results ◽  
Time Data ◽  
Grab Sampling

Abstrak – Penelitian ini bertujuan untuk mengkaji pengaruh waktu paparan gelombang ultrasonik terhadap pengurangan jumlah koloni bakteri coliform pada sampel air sungai Kahayan. Pengambilan sampel air sungai dilakukan dengan teknik Grab Sampling menggunakan alat Kemmerer Sampler. Sampel air yang didapatkan diberikan paparan gelombang ultrasonik secara langsung, tanpa merubah kondisi lingkungan awal. Waktu paparan divariasikan pada 1 jam, 2 jam, 3 jam, 4 jam, dan 5 jam dengan frekuensi 40 kHz untuk memperoleh data waktu optimum. Uji coliform dilakukan dengan metode MPN, dengan tahapan uji pendugaan, uji penegasan, dan perhitungan koloni. Hasil uji MPN 24 jam setelah paparan menunjukkan bahwa penggunaan ultrasonik sebagai antibateri dapat optimum ketika diberikan paparan dengan waktu 3 jam, dengan efisiensi  96%. Kata kunci: antibakteri, coliform, ultrasonik, water treatment, sungai Kahayan  Abstract – This study aims to examine the effect of ultrasonic wave exposure time on reducing the number of coliform bacterial colonies in the Kahayan river water samples. River water sampling is done using the Grab Sampling technique using the Kemmerer Sampler tool. The water samples obtained were given direct ultrasonic wave exposure, without changing the initial environmental conditions. The exposure time is varied in 1 hour, 2 hours, 3 hours, 4 hours and 5 hours with a frequency of 40 kHz to obtain optimum time data. Coliform test was carried out by the MPN method, with the stages of the estimation test, affirmation test, and colony calculation. The MPN test results 24 hours after exposure showed that the use of ultrasonic as an antibody can be optimum when given exposure with a time of 3 hours, with an efficiency of 96%.Keywords : antibakterial, coliform, ultrasonic, water treatment, Kahayan river

Design of experimental food patches to measure foraging intensity for octopus: a case study with the giant Pacific octopus Enteroctopus dofleini

2020 ◽  
Author(s):  
Stephanie Chancellor ◽  
David Scheel ◽  
Joel S Brown
Keyword(s):  
Predation Risk ◽  
Foraging Behaviour ◽  
Habitat Preferences ◽  
High Tide ◽  
Intertidal Habitat ◽  
Camera System ◽  
Subtidal Habitat ◽  
Enteroctopus Dofleini ◽  
Nontarget Species

ABSTRACT In a study of the foraging behaviour of the giant Pacific octopus Enteroctopus dofleini, we designed two types of experimental food patches to measure habitat preferences and perceptions of predation risk. The first patch successfully measured giving-up densities (GUDs), confirmed by octopus prey presence and higher foraging at sites with historically greater octopus presence. However, nontarget foragers also foraged on these experimental food patches. Our second floating patch design successfully excluded nontarget species from subtidal patches, and from intertidal patches at high tide, but allowed for foraging by E. dofleini. The second design successfully measured GUDs and suggested that octopus preferred foraging in a subtidal habitat compared to an intertidal habitat. We ascribe the higher GUD in the intertidal habitat to its higher predation risk relative to the subtidal habitat. The second patch design seems well suited for E. dofleini and, in conjunction with a camera system, could be used to provide behavioural indicators of the octopus's abundance, perceptions of habitat quality and predation risk.

scholarly journals Simulations with Australian dragon lizards suggest movement-based signal effectiveness is dependent on display structure and environmental conditions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xue Bian ◽  
Angela Pinilla ◽  
Tom Chandler ◽  
Richard Peters
Keyword(s):  
Research Methods ◽  
Environmental Conditions ◽  
Comparative Studies ◽  
Habitat Structure ◽  
Signal Transmission ◽  
Lizard Species ◽  
Local Adaptations ◽  
Signal Divergence ◽  
Colour Signals ◽  
Optimal Signal

AbstractHabitat-specific characteristics can affect signal transmission such that different habitats dictate the optimal signal. One way to examine how the environment influences signals is by comparing changes in signal effectiveness in different habitats. Examinations of signal effectiveness between different habitats has helped to explain signal divergence/convergence between populations and species using acoustic and colour signals. Although previous research has provided evidence for local adaptations and signal divergence in many species of lizards, comparative studies in movement-based signals are rare due to technical difficulties in quantifying movements in nature and ethical restrictions in translocating animals between habitats. We demonstrate herein that these issues can be addressed using 3D animations, and compared the relative performance of the displays of four Australian lizard species in the habitats of each species under varying environmental conditions. Our simulations show that habitats differentially affect signal performance, and an interaction between display and habitat structure. Interestingly, our results are consistent with the hypothesis that the signal adapted to the noisier environment does not show an advantage in signal effectiveness, but the noisy habitat was detrimental to the performance of all displays. Our study is one of the first studies for movement-based signals that directly compares signal performance in multiple habitats, and our approach has laid the foundation for future investigations in motion ecology that have been intractable to conventional research methods.

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