Suitable habitats of two coastal cetaceans along the northern Arabian Sea: Important marine mammal areas susceptible to conservation gaps

Abstract

1. Coastal cetaceans are often selected as a biodiversity surrogate in ecosystembased conservation planning. In the northern Arabian Sea there is insufficient information on suitable habitats for the Indo-Pacific finless porpoise and Indian Ocean humpback dolphin for planning protection.2. Suitable habitats for the Indo-Pacific finless porpoise and Indian Ocean humpback dolphin were projected using the MaxEnt model in the present study. The variable contributions in MaxEnt exercises and characteristics of the major habitats were used to represent the ecological niches of these two cetaceans.3. Along coastal waters of the northern Arabian Sea, bathymetry was the most significant variable that influenced the distribution of the Indian Ocean humpback dolphin, which prefers water 2-5 m deep. The Indo-Pacific finless porpoise prefers 6-20 m deep water and its distribution was influenced by bathymetry, sea-surface temperature and chlorophyll-a concentration.4. Suitable habitats identified by this study provide a baseline from which to evaluate the impact of anthropogenic activities in coastal and estuarine waters, assist marine development planning and guide marine protected area (MPA) designations. Effective MPA designation would include ca. 30% of major habitats to accommodate viable populations and sufficient biodiversity richness to maintain a functioning ecosystem. Data used in the present study may be subject to sampling heterogeneity and thus coastal waters not included as suitable habitats would require further investigation for possible omission bias. Actions necessary for conservation of the Indo-Pacific finless porpoise and IndianOcean humpback dolphin include designating no-take zones or MPAs, banning industrial fishing while restricting artisanal fishery activity and mobilizing community-based conservation campaigns for major habitat protection. As such, further data on distribution, density and environmental variables related to cetaceans are needed to inform any conservation efforts.

The distribution and habitat characterization of the East Asian finless porpoise (Neophocaena asiaeorientalis sunameri) in coastal waters off Qingdao, China: Implications for management and conservation

“…Since 2007, only a few opportunistic surveys have been conducted throughout this species' range (Choi et al, 2021; Li et al, 2023; Park et al, 2015; Shirakihara et al, 2019). As effective conservation planning relies on robust baseline data (Huang, 2022; Kiani et al, 2023), the following actions are highly recommended to resolve the current data deficiency. At the initial stages of research into the East Asian finless porpoise, applying local ecological knowledge (LEK) and stranding reporting schemes can be highly effective. These approaches facilitate the acquisition of long‐term, large‐scale, meaningful and conservation‐relevant background information within a condensed period of data collection, offering a robust foundation for subsequent detailed studies (Liu et al, 2022).…”

“…Since 2007, only a few opportunistic surveys have been conducted throughout this species' range (Choi et al, 2021;Li et al, 2023;Park et al, 2015;Shirakihara et al, 2019). As effective conservation planning relies on robust baseline data (Huang, 2022;Kiani et al, 2023), the following actions are highly recommended to resolve the current data deficiency.…”

“…Dähne et al, 2013; Haughey et al, 2021; Hooker et al, 1999; Peter et al, 2016; Wilson et al, 2004). Beyond MPA management, these datasets play a critical role in broader marine spatial planning efforts, including strategies for habitat protection and logistics for the development of marine infrastructures like offshore wind energy projects (Huang, 2022; Kiani et al, 2023).…”

Eye in the Sky: Modeling Spatial Distribution of Antillean manatees (Trichechus manatus manatus) in St. George’s Caye, Belize

“…Maxent is commonly used in marine mammal spatial distribution and ecological niche modeling, especially when absence data is unavailable (Kiani et al, 2023). This method has been successful in predicting marine mammal distributions (Friedlaender et al, 2011, Tobeña et al, 2016Svendsen et al, 2015).…”

“…While our outcomes represent a successful approach to fine-scale species distribution modeling, we do acknowledge possible biases and modeling challenges. Although popular and widely used, SDMs are typically prone to uncertainties due to model parametrization, selection, and field survey design (Kiani et al, 2023;Rocchini et al, 2011;Wang et al 2021). SDMs are valuable for inferring suitable habitat in unsampled locations, but inherent bias can limit model reliability (Merow et al, 2013;.…”