Monitoring multi-temporal and spatial variations of water transparency in the Jiaozhou Bay using GOCI data

Water transparency, commonly measured as Secchi disk depth (SDD), is essential for describing the optical properties of coastal waters. We proposed a regional linear corrected SDD estimation model based on the North Sea Mathematical Models for GOCI and the mechanical model developed by Lee et al. (2015) in the Jiaozhou Bay. Combined with the multiple variable linear regression analysis, the diurnal SDD variations of the bay inside and the bay mouth are controlled by the solar zenith angle (SZA) and tides. The bay outside mainly varies with SZA. From GOCI observations between 2011 and 2021, wind force influenced the entire area on the inner-annual SDD variations. It exhibits an increasing trend in the inter-annual dynamics, which was more stable inside the bay with an annual increase of 0.035 m, and air temperature was the most significant contribution. However, human activities cannot be ignored in causing water environment changes

Capturing secchi disk depth by using sentinel-2 msi imagery in Jiaozhou Bay, China from 2017 to 2021

Water clarity is a key parameter for assessing changes of aquatic environment. Coastal waters are complex and variable, remote sensing of water clarity for it is often limited by low spatial resolution. The Sentinel-2 Multi-Spectral Instrument (MSI) imagery with a resolution of up to 10 m are employed to solve the problem from 2017 to 2021. Distribution and characteristics of Secchi disk depth (SDD) in Jiaozhou Bay (JZB) are analyzed. Subtle changes in localized small areas are discovered, and main factors affecting the changes are explored. Among natural factors, precipitation and wind play dominant roles in variation in SDD. Human activities have a significant influence on transparency, among which fishery farming has the greatest impact. This is clearly evidenced by the significant improvement of SDD in JZB due to the sharp decrease in human activities caused by coronavirus disease 2019 (COVID-19)

Annual report 1996 - North Pacific Marine Science Organization (PICES). Fifth meeting, Nanaimo, British Columbia, Canada, October 11-20, 1996

Proceedings of the Fifth Annual Meeting Agenda Report of Opening Session Report of Governing Council Meetings Reports of Science Board and Committees Science Board Working Group 5: Bering Sea (Final Report) Working Group 9: Subarctic Pacific Monitoring Report of the First Meeting Report of the Second Meeting Biological Oceanography Committee Working Group 11: Consumption of Marine Resources by Marine Birds and Mammals Fishery Science Committee Working Group 12: Crabs and Shrimps Marine Environmental Quality Committee Working Group 8: Practical Assessment Methodology Physical Oceanography and Climate Committee Working Group 10: Circulation and Ventilation in the Japan Sea /East Sea and its Adjacent Areas Technological Committee on Data Exchange Finance and Administration Report of Finance and Administration Committee Assets on 31st of December, 1995 Income and Expenditures for 1995 Budget for 1997 Composition of the Organization Officers, Delegates, Finance and Administration Committee, Science Board, Secretariat, Scientific and Technical Committees List of Participants List of Acronyms (Document has 163 pages.

Coastal wetland mapping with sentinel-2 MSI imagery based on gravitational optimized multilayer perceptron and morphological attribute profiles.

Coastal wetland mapping plays an essential role in monitoring climate change, the hydrological cycle, and water resources. In this study, a novel classification framework based on the gravitational optimized multilayer perceptron classifier and extended multi-attribute profiles (EMAPs) is presented for coastal wetland mapping using Sentinel-2 multispectral instrument (MSI) imagery. In the proposed method, the morphological attribute profiles (APs) are firstly extracted using four attribute filters based on the characteristics of wetlands in each band from Sentinel-2 imagery. These APs form a set of EMAPs which comprehensively represent the irregular wetland objects in multiscale and multilevel. The EMAPs and original spectral features are then classified with a new multilayer perceptron (MLP) classifier whose parameters are optimized by a stability-constrained adaptive alpha for a gravitational search algorithm. The performance of the proposed method was investigated using Sentinel-2 MSI images of two coastal wetlands, i.e., the Jiaozhou Bay and the Yellow River Delta in Shandong province of eastern China. Comparisons with four other classifiers through visual inspection and quantitative evaluation verified the superiority of the proposed method. Furthermore, the effectiveness of different APs in EMAPs were also validated. By combining the developed EMAPs features and novel MLP classifier, complicated wetland types with high within-class variability and low between-class disparity were effectively discriminated. The superior performance of the proposed framework makes it available and preferable for the mapping of complicated coastal wetlands using Sentinel-2 data and other similar optical imagery

Seagrass distribution changes in Swan Lake of Shandong Peninsula from 1979 to 2009 inferred from satellite remote sensing data

Seagrass and associated bio-resources are very important for swan’s overwintering in Swan Lake in Rongcheng of Shandong Peninsula of China. The seagrass distribution changes, which are usually affected by the regional human activities, can indirectly affect swan’s habitat. In this study the satellite remote sensing data in years 1979–2009 together with in-situ observations in recent years were used to examine the seagrass distribution changes in Swan Lake. The band ratio of band 1 to band 2, Lyzenga’s methods and band synthesize of band 1, band 2 and band 3 were used for seagrass retrieval. The band ratio of band 1 to band 2 with ranges greater than 4.5 was used for estimating the seagrass coverage greater than 50%. Results showed that in years 1979–1990 seagrass coverage greater than 50% occupied more than half of the surface area of Swan Lake. In years 2000–2005, the total area with seagrass distributions reduced greatly, only about one sixth to one fourth of Swan Lake’s surface area. After 2005, the seagrass area in Swan Lake increased gradually and occasionally was greater than one third of the total surface area of the Lake. It was shown that human activities such as the dam and fish pond establishment and the awareness of seagrass importance and protected actively result in the seagrass distributions changes in Swan Lake which decreased first and then increased afterwards

Unexpected Diversity of Magnetococci in Intertidal Sediments of Xiaoshi Island in the North Yellow Sea

Magnetotactic bacteria (MTB) are a group of prokaryotes that, despite their high morphological, phylogenetic, and ecological diversity, share a common capability of forming intracellular nanocrystals of magnetite (Fe3O4) or greigite (Fe3S4), called magnetosomes, and swimming along geomagnetic field lines in a process called magnetotaxis. In this study, we investigated the MTB diversity within the intertidal sediments near Xiaoshi Island (Weihai) in the North Yellow Sea using a combination of molecular ecology techniques and transmission electron microscopy (TEM). The combination of restriction fragment length polymorphism (RFLP) analysis and 16S rRNA gene sequencing revealed seven new MTB genera affiliated with the Alphaproteobacteria class. Fluorescence in situ hybridization (FISH) analyses suggested that one magnetotactic coccus (designated as WHI-2) is the dominant species. TEM observations and energy dispersive X-ray analyses revealed that MTB cells mainly form magnetite magnetosomes that are organized into two chains of magnetosomes composed of e-prismatic magnetite crystals. This finding suggests the adaptation of a magnetotactic bacterial population to the marine tide. This is the first report of magnetotactic bacteria near Xiaoshi Island, which should be useful for studies of biogeochemical cycling and the geohistory of this area

Optical Satellite Remote Sensing of the Coastal Zone Environment — An Overview

Optical remote-sensing data are a powerful source of information for monitoring the coastal environment. Due to the high complexity of coastal environments, where different natural and anthropogenic phenomenon interact, the selection of the most appropriate sensor(s) is related to the applications required, and the different types of resolutions available (spatial, spectral, radiometric, and temporal) need to be considered. The development of specific techniques and tools based on the processing of optical satellite images makes possible the production of information useful for coastal environment management, without any destructive impacts. This chapter will highlight different subjects related to coastal environments: shoreline change detection, ocean color, water quality, river plumes, coral reef, alga bloom, bathymetry, wetland mapping, and coastal hazards/vulnerability. The main objective of this chapter is not an exhaustive description of the image processing methods/algorithms employed in coastal environmental studies, but focus in the range of applications available. Several limitations were identified. The major challenge still is to have remote-sensing techniques adopted as a routine tool in assessment of change in the coastal zone. Continuing research is required into the techniques employed for assessing change in the coastal environment

Effects of an allelochemical in Phaeodactylum tricornutum filtrate on Heterosigma akashiwo : morphological, physiological and growth effects

© The Author(s), 2017. This is the author's version of the work. It is posted here under a nonexclusive, irrevocable, paid-up, worldwide license granted to WHOI. It is made available for personal use, not for redistribution. The definitive version was published in Chemosphere 186 (2017): 527-534, doi:10.1016/j.chemosphere.2017.08.024.The effects of an allelochemical extracted from the culture filtrate of diatom Phaeodactylum tricornutum on the raphidophyte Heterosigma akashiwo were investigated using a series of morphological, physiological and biochemical characters. Growth experiments showed that H. akashiwo was significantly inhibited immediately after exposure to the allelochemical, with many cells rapidly dying and lysing based on microscopic observation. The effects of the allelochemical on the surviving cells were explored using Scanning Electron Microscopy (SEM) and Flow cytometry (FCM), the latter by examination of a suite of physiological parameters (membrane integrity, esterase activity, chlorophyll-a content, membrane potential). The results demonstrate that the membrane of H. akashiwo was attacked by the allelochemical directly, causing cell membrane breakage and loss of integrity. Esterase activity was the most sensitive indicator of the impacts of the allelochemical. Membrane potential and chlorophyll-a content both showed significant decreases following exposure of the Heterosigma cells to high concentrations of the allelochemical for 5 and 6 days. Both were affected, but the membrane potential response was more gradual compared to other effects. The cell size of H. akashiwo did not change compared with the control group. The surviving cells were able to continue to grow and in a few days, re-establish a successful culture, even in the presence of residual allelochemical, suggesting either development of cellular resistance, or the degradation of the chemical.The authors wish to thank the National Programme on Global Change and Air-Sea Interaction (Grant No. GASI-03-01-02-01); the National Key Research and Development Program [Grant No. 2016YFC1402101]; the assessment of nanomaterials on biological and ecological effects in the coastal area (Grant No. 201505034)