Dear readers of and contributors to Marine and Environment,

It is with great pleasure that we present the inaugural issue of Marine and Environment for the year, featuring a captivating Section Collection on “Studies of the Seabed”. This collection showcases the remarkable progress made in understanding the dynamic nature of the seabed and the vital role it plays in marine ecosystems. These studies explore various aspects of the seabed’s behavior and response to natural and human-induced disturbances, such as earthquakes, landslides, waves, currents, sediment transport, erosion, deposition, mining, drilling, anchoring, cable laying, and offshore structures^[1,2]. As the editorial team, we are thrilled to present a compilation of cutting-edge research articles that delve into the intriguing world of seabed mechanics and dynamics, which has the potential to shape our future in profound ways.

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Deep neural networks have been increasingly used to identify individual animals in ecological studies by learning and distinguishing their naturally occurring marks or features. Traditional individual animal recognition requires prior knowledge and experience, which can be time-consuming and inefficient. In this paper, a distinctive deep learning framework that automatically reidentifies individual Indo-Pacific humpback dolphins (Sousa chinensis) from photos was proposed. For most dolphin species with a dorsal fin, this feature is reliably used to identify and distinguish individuals in studies that require distinction between members of a group or population. Feature cutting and background removing strategies were added to allow a focus on local information. Knowledge distillation was also applied to improve the robustness of the framework. Additionally, an automatic dolphin recognition software suite for cetologists that may reduce the amount of effort and time required to manually confirm individual dolphin ID from photographs had been developed. In the end, the effectiveness of applying this deep neural network approach for individual Indo-Pacific humpback dolphin recognition had been demonstrated.

China’s beaches exhibit different geomorphic characteristics depending on location. Due to increasing contemporary climate change, induced storm activities and human activities, beaches along the Chinese coast have been exposed to the risk of erosion. This article examines the different shoreline evolution processes from 1973 to 2021 as well as the erosion vulnerability of 9 headland-embayed beaches (of which 5 beaches, each at Baishawan, Dasha, Dongdan, Nanshajiao, and Mushao are on the muddy coast in Southern China and 4 beaches, namely, Bathing Beach 1, 2, 3 and Shilaoren Beach are on the sandy coast in Northern China) based on the inherent geomorphic characteristics and nearshore hydroclimatic factors of the beaches. In the analysis, there were 3 stages. During the first stage, erosion dominated both the muddy and sandy coasts as a result of intense storm conditions. During the second stage, the beaches had earlier recovered as a function of natural processes, however, storm activities later eroded the beaches. During the third stage, most of the beaches accreted as a result of coastal engineering interventions and beach nourishment project. The shoreline analysis results indicate that beaches on the muddy and sandy coasts have been eroding in the long term. During the first erosion stage, erosion is more severe on the muddy coast than on the sandy coast in the short term. On the sandy coast, the beaches recorded severe erosion from 1973 to 1998. Of the 9 beaches, the most eroded location was at Dasha on the muddy coast (LRR: –5.315 m/y; EPR: –5.671 m/y; NSM: –141.94 m) between 1974 and 1998. In summary, beaches on muddy coasts are more vulnerable to erosion than those on sandy coasts. On the muddy coast, there has been a shortage in the supply of sediment from the Yangtze River-derived sediment to the coast. The primary source of sand material for the studied beaches on the muddy coast has been the regular storm condition that changes the sand-mud transition line on the coast. For the sandy beaches, the primary factor responsible for the vulnerability and beach modification includes a shortage in the natural supply of beach material and storm activities, however, recent beach nourishment and coastal protection procedures are gradually stabilizing the beaches. Ultimately, the outcome of this research is suitable for beach management procedures on the Chinese coast.

This study presents a new interpretation of the seismic stratigraphic unit equivalent to the Late Cretaceous to Pliocene formations in the Salin basin. Many researchers investigated the outcrops of the stratigraphic succession of the Salin basin but there is a lack of comprehensive analysis by seismic interpretation. This study provides a comprehensive description of the structural development within the Salin basin, enhancing our comprehension of the regional stratigraphic evolution of the examined region. Seismic sequences were delineated using a combination of horizon mapping, internal reflection configuration, termination patterns, and thickness analysis. We identified two distinct mechanisms for lateral fault seals: (1) primary juxtaposition seals and (2) secondary fault rock seals (also known as membrane seals). Once the hydrocarbons are matured within the source formations (Late Cretaceous to Early Oligocene shales units): Kabaw (KB); Laungshe (LA); Tabyin (TA); Pondaung (PO); Yaw (YA); and Shwezettaw (SZT), they are migrated towards the reservoir formations (Pondaung (PO), Shwezettaw (SZT), Padaung (PA), Okhmintaung (OHK), and Kyaukkok (KK)) through these predicted paths. Generally, the primary migration takes place along the fault or fractured planes or pores within rock units. In the southwestern limb of the Yenangyaung anticline, the disharmonic folding and upward bending of the KK, PY, OHK, and PA formations resulted in the deformation of ductile strata within the PA Formation, forcing them towards the peripheral synclines. The main deep fore-thrust in the southwestern limb of the Chauk anticline rooted within the PA Formation flattened up while approaching the OHK and PY formations. Chauk anticlinal axis above the PY and OHK detachment level are more migrated toward the northeast. As a result, above the crest of the deep anticline, the shallow low-angle fore-thrust pushed up into the growth strata, leading to the uplift of the YA and SZT formations within the Letpando anticline. YA Formation crops out locally along the axis of the structure and is the major seal, with sandstones in the underlying Eocene PO Formation being the main reservoir.