Conservation planning for threatened marine megafauna: Moving forward with a better approach

Abstract

1. For threatened marine megafauna, such as the Indo-Pacific humpback dolphin (Sousa chinensis), sound conservation planning should aim to ensure demographic and ecological persistence of populations. One method to address this challenge is through ecosystem-based conservation planning (ECP) based on threatened marine megafauna distribution, biodiversity richness, and ecosystem functionality. 2. ECP exercises for the Indo-Pacific humpback dolphin in Chinese and adjacent northern Vietnamese waters were conducted based on the Indo-Pacific humpback dolphin distribution, Hill-2 biodiversity index, and marine net primary productivity. Habitat protection priorities were scored using the program MARXAN and were used to identify special areas for conservation (SACs) for the Indo-Pacific humpback dolphin. 3. To ensure the minimal risk of local extinction, the SACs enclosed a total of 26,858 km 2 of waters, accounting for 49.9% of core habitats of the Indo-Pacific humpback dolphin and 24.3% of the IUCN Red List species in the study region. To enclose 30% of biodiversity richness and ecosystem functionality, a total of 40,179 km 2 SACs was required. 4. In the context of threatened marine megafauna conservation, megafauna distribution can be used to highlight focal areas, while information on biodiversity richness and ecosystem functionality should be factored in. Using surrogates with different ecological niches would be a better tactic to ensure sufficient protection coverage by minimizing the omission bias. 5. The conservation of threatened marine megafauna in coastal and estuarine waters shares similar objectives with global marine biodiversity conservation. The challenges to conduct ECP exercises come from data scarcity and poor data quality in representing distributions of biodiversity features. A certified openaccess database that shares survey effort, occurrence, population density, and habitat mapping at national and local scales is recommended. Such a result requires national planning, investment, and policing. Shiang-Lin Huang and Haiping Wu contributed equally to this article.

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

“…The first step towards these measures could be delineating no‐take zones for fishing management and MPAs for marine biodiversity conservation (Di Tullio, Fruet & Secchi, 2015). For vulnerable marine mammals, effective MPA designation needs to provide sufficient area to accommodate a viable population and ensure a high level of biodiversity richness to maintain a functioning ecosystem (Karczmarski, Huang & Chan, 2017; Huang et al, 2022). For the Indian Ocean humpback dolphin, the minimum area to ensure population survival has not yet been estimated.…”

“…Industrialized fishing must be banned in the LCHs of these species. Artisanal fisheries, particularly those associated with household livelihoods, need to be regulated and restricted to minimize the level of activity in the LCHs (Di Tullio, Fruet & Secchi, 2015;Wu et al, 2022), along with livelihood diversification and organizing community-based conservation campaigns (Wu et al, 2022). The LCHs of the Indo-Pacific finless porpoise and Indian Ocean humpback dolphin should be designated as 'no-go' areas for maritime engineering projects, such as wind farm developments (Huang, 2022) and oil extraction.…”

“…Since 2009, only a few opportunistic cetacean surveys have been conducted in Pakistan's waters (Kiani & Van Waerebeek, 2015). As effective conservation planning relies on robust baseline data (Huang et al, 2020;Huang et al, 2022), the following actions are highly recommended to resolve the current data deficiency in the northern Arabian Sea. 3.…”

“…Holistic conservation measures aim to protect threatened marine biota, biodiversity richness and ecosystem functionality (IUCN, 2016a; Davidson & Dulvy, 2017; Cook et al, 2019; Wang et al, 2021) through a variety of spatial zoning tools (Bax et al, 2016; Dunstan et al, 2016; IUCN, 2016b; IUCN‐MMPATF, 2020). In ecosystem‐based conservation planning, marine megafauna such as cetaceans are often used as surrogates (Hooker & Gerber, 2004; Wang et al, 2021; Huang et al, 2022) owing to their wide‐ranging movement, distribution and preference for areas of great biodiversity richness (Wu et al, 2017; Sequeira et al, 2019). For cetaceans inhabiting coastal and estuarine ecosystems, protecting their major habitats, i.e.…”

“…For cetaceans inhabiting coastal and estuarine ecosystems, protecting their major habitats, i.e. the areas used for aggregation, feeding, nurseries and the socializing of animals (Wang et al, 2016b), is important for ensuring cetacean population survival (Karczmarski, Huang & Chan, 2017) and maintaining functioning ecosystems (Wu et al, 2017; Wang et al, 2021; Huang et al, 2022).…”