Endangered Species

To test whether ED scores are comparable among taxonomic groups, we examined how species' ED accumulates as progressively larger clades are considered. If ED scores are truly comparable, their rank order will be independent of the size of the clade considered. We randomly selected one Critically Endangered species from each of ten mammal orders and measured the cumulative ED score at each node between the species and the root of the mammal supertree, thus redefining and enlarging the clade (and so increasing the number of species it contained) at each step.
Taxonomic changes have the potential to dramatically alter the ED scores of individual species. Splitting a species in two reduces the distinctiveness of all branches ancestral to the split, particularly those near the tips. If ED scores are highly sensitive to taxonomic changes then it may be meaningless to apply them in setting conservation priorities. The effects of taxonomic changes on ED scores were therefore investigated in the primates, which have recently experienced considerable taxonomic inflation [27] (link). We compared primate ED scores under a biological species concept [35: 233 species] and a phylogenetic species concept [36: 358 species] . We employed a single phylogeny [31] , but changed the number of species represented by each tip. We calculated the expected ED for multi-species tips by treating them as if they were descended from a polytomy of {n+r+1} descendent branches, where n is the actual number of descendent branches and r is the number of species represented by the tip.

Nine adult specimens of the cardinal fish species, Nectamia savayensis (Order: Perciformes; Family: Apogonidae; total length = 59-83 mm), three specimens of soldierfish, Myripristis berndti (Order: Beryciformes; Family: Holocentridae; total length = 114-143 mm), and four specimens of the squirrelfish, Sargocentron microstoma (Order: Beryciformes; Family: Holocentridae; total length = 148-161 mm) were collected by spear-fishing on the 9th of August 2010, two hours after sunset in the lagoon of the North shore of Moorea Island, French Polynesia (17°30’S, 149°50’W). The three nocturnal fish species vary in their feeding mode and habitat use: N. savayensis occurs in the water column between two and three meters and is strictly planktivorous; M. berndti was collected from near reef crevices at four meters and consumes both planktonic and benthic prey; S. microstoma is also a benthic predator but preys upon larger benthic invertebrates
[39 ,40 ]. Approval was granted from our institutional animal ethics committee, le Centre National de la Recherche Scientifique (CNRS), for sacrificing and subsequently dissecting fish (Permit Number: 006725). None of the fish species are on the endangered species list and no specific authorization was required from the French Polynesian government for collection.
Fish were preserved in cold 50% ethanol in the field. Their digestive systems were dissected within 2 hours in the laboratory and preserved in 80% ethanol at −20°C. After storage for 2 months, total genomic DNA was extracted from the total prey mixture contained in the digestive track using QIAGEN® DNeasy Blood & Tissue individual columns. Genomic DNA was purified using the MOBIO PowerClean DNA clean-up kit to prevent interference with PCR inhibitors.

To examine the effect of number of research articles and news coverage on public interest in conservation topics by the online public, we selected specific conservation-themed keywords. The criteria for selecting keywords were: (i) words or phrases representing major areas of research in conservation biology; (ii) words or short phrases which are specific and not prone to confusion with other popular, non-conservation search keywords (e.g. tiger or PES (payment for ecosystem services) may be used to refer to a famous golfer or a popular video game respectively, so were excluded); (iii) overlap with previous studies looking at online interest in environmental topics ([12 ], [13 ]); and (iv) words or phrases with sufficient search volume in Google Trends to facilitate the analysis (e.g. wildlife consumption was discarded for this reason). The final seven keywords selected were: climate change, ecosystem service (or ecosystem services), deforestation, orangutan (or orang-utan), invasive species, endangered species, and habitat loss. Though these keywords did not purport to be a comprehensive representation of conservation topics, each keyword represents a real-world, topical conservation issue that can be illustrative for our approach.
We used the search volume in Google Trends as a proxy for changes in public interest across a 10-year period, starting from January 2004 (when Google Trends data were first available) until December 2013. Search volume in Google Trends is the traffic for a specific keyword relative to all queries submitted in Google, normalized to range from 0 to 100, with 100 corresponding to the peak of relative search volume obtained for each keyword during the period of interest [7 ].
To correct for shifting baselines in overall search volume, we transformed relative monthly search volume for each keyword by dividing it by a benchmark term. We chose four terms spanning a range of non-decreasing to increasing interest to assess the sensitivity of this correction to the choice of benchmark term. The benchmark terms selected were: software, computer, life and love. The choice of these terms is based on suggestions from previous studies. Actual public interest in software and computer presumably remains consistent and these two terms can be used as neutral terms [13 ]. Love and life, on the other hand, are popular terms with presumably increasing popularity in the social web and news archives [25 (link)] and used as benchmark keywords in related research on public interest in the environment across different languages [26 ]. Statistical analyses were conducted on the benchmark-corrected data in the R environment [27 ].

The Smithsonian Conservation Biology Institute (SCBI) manages a captive herd of scimitar-horned oryx to facilitate breeding, scientific research and contribute to the in situ and ex situ conservation of the species. SCBI is a 1,440-ha facility for research and conservation of endangered species and their ecosystems and is located outside the town of Front Royal, VA, in the foothills of the Appalachian Mountains (Figures 1A, B). The scimitar-horned oryx herd at SCBI is maintained in several enclosures over an area of 7.47 ha (Figure 1B). Animals are moved between fenced pastures with free access to grazing and to shelters or barn facilities that protect animals from the weather and enable veterinary and animal care procedures. We selected eight adult scimitar-horned oryx (Figure 1C) for this study: one vasectomized male and seven non-pregnant females (Table 1). Initially, the studied animals were part of a social group of 18 adult females, five offspring of the year and the vasectomized male (“Sweeny”). After about 6 months, the male was permanently separated from the female herd and transferred to his own pasture and barn, in visual and olfactory proximity to other oryx. Animal care personnel interacted twice daily with scimitar-horned oryx for feeding, check-ups, care, and cleaning of the barn at approximately 08h00 and 14h00 local time. The animals had free access to pastures and hay and received pellet food once a day at about 15h00. Between August and November 2019, the female herd was temporarily kept in the largest grazing area (outlined by white lines in Figure 1B) due to barn maintenance.

A total of 66 Eleutheronema tetradactylum individuals were collected through commercial fishing in Southern China from five locations: Zhangzhou (ZZ), Naozhou (NZ), Jianghong (JH), Dongxing (DX), and Wenchang (WC) (Table 1, Fig. 1), across a spatial scale of 1200 km. The samples from NZ were collected twice (Nov. 2020 and Nov. 2021), whereas the sampling from other four locations were collected in Nov. 2021. Fourfinger threadfin individuals were sampled by commercial fishery boats. Due to the high price in local fish markets and vulnerable state of this endangered species, the number of samples in this study was relatively low. Nonetheless, some previous studies demonstrated the efficacy of otolith microchemistry in revealing fish life history and population structure based on small sample sizes^{29 (link),30 (link)}. Although previous studies reported E. tetradactylum in the East China Sea and the South China Sea^{31 (link),32 (link)}, our survey on the important fishing ports along the coasts of China from Yangtze River estuary to Guangxi only found E. tetradactylum at the coasts of Southern China. Based on the von Bertalanffy growth curve of E. tetradactylum fitted by the previous study³³ , we used the total length of each specimen in this study to estimate the age of E. tetradactylum samples, and all individuals were of the same age (4 +).Table 1

Sampling locations and sample characteristics of fourfinger threadfin, Eleutheronema tetradactylum, collected from China.

Location	Sampling date	Population code	Number	Total length (cm, mean ± SD)
Zhangzhou	2021.11	ZZ	7	62.2 ± 2.36
Naozhou 2021	2021.11	NZ-21	13	60.3 ± 4.12
Naozhou 2020	2020.11	NZ-20	15	61.3 ± 3.97
Jianghong	2021.11	JH	15	59.0 ± 3.57
Dongxing	2021.11	DX	7	61.0 ± 2.00
Wenchang	2021.11	WC	9	62.8 ± 4.32

Figure 1

The locations where the fourfinger threadfin, Eleutheronema tetradactylum, were collected. (A) The different colored areas on the land represent the different basins along the southern coast of China, Oujiang Basin (OJ), Mindong Basin (MD), Minjiang Basin (MJ), Minnan Basin (MN), Hanjiang Basin (HJ), Zhujiang Basin (ZJ), Yuexi Basin (YX), Guinan Basin (GN). Red dots show the sample sites. (B) The green arrow symbol is the schematic representation of currents. The map was drawn using open source software QGIS 2.14 (http://www.qgis.org/). The base map was downloaded from the Natural Earth (open access) at https://www.naturalearthdata.com/. The boundary of different basins was extracted from HydroBASINS at https://www.hydrosheds.org/products/hydrobasins.

DX was located on the westernmost coast of China, and JH and NZ were located on the west and east sides of Leizhou Peninsula in Southern China, respectively. DX and JH were both adjacent to the Beibu Gulf, and NZ was located on the western Guangdong where water exchange between the coastal waters of western Guangdong and Beibu Gulf took place through the Qiongzhou Strait. The Guangdong Western Coastal Current (GDWCC) moves westward during most of the year but shifts eastward during the monsoon season^{34 (link),35 (link)}. WC was located on the east side of Hainan island. ZZ was adjacent to the Taiwan Strait, and distant from other sites (~ 1200 km distance from DX, ~ 900 km distance from WC). During winter the Guangdong Coastal Current (GDCC) from Guangdong moves westward to the southeast of Hainan island^{34 (link)}.
As estuaries are the transition zones linking freshwater and marine environments, their environmental and hydrological processes are largely governed by the degree of freshwater inflow^{36 (link),37 (link)}. Therefore, the freshwater inflow may be an important environmental variable affecting fish recruitment^{36 (link),38 (link),39 (link)}. Freshwater inflow to an estuary is usually related to runoff directly, although there are estuaries that receive freshwater from springs^{36 (link)}. In this study, runoff in coastal basins throughout the coast of Southern China was used as a proxy for freshwater inflow to assess the interannual variation in habitat availability (the boundary of the basin is shown in Fig. 1). We accessed ERA5-Land ECMWF Climate Reanalysis to extract the regional average monthly runoff data from January of 2016 to December of 2020⁴⁰ . To make the data comparable across years and basins, we used the average values of runoff of each basin (Fig. 2).Figure 2

Average monthly runoff of the basins throughout coast of Southern China from January of 2016 to December of 2020. The 12 facets represent the months from January to December. Horizontal line in box: median value; bottom and top of box: 25th and 75th percentiles; whiskers: 5th and 95th percentiles.

All use of animals in this study was approved by the Toronto Zoo (Ref. No. 2010-01-01, 2014-03-01, 2015-04-01, 2017-03-01, 2020-02-01) and Laurentian University (protocols AUP 2017-02-01 and 6020983) Animal Care Committees. All work was authorized by Ministry of Northern Development, Mines, Natural Resources, and Forestry (NDMNRF) Scientific Collector’s Authorizations (1077386, 1080550, 1083631, 1086727, 1089107/Local Ref. No. AU2018-0533, 1092095/Local Ref. No. AU2019-1299, and 1095690/Local Ref. No. AU2020-2325), Endangered Species Act permits (AU-B-010-14, AU-B-008-15, AU-B-011-16, AU-B-008-17, AU-B-009-18), and Parks Canada Species at Risk Act permits (RNUP-2020-35017). We obtained informed written consent from all organizations.