Threatened Species Nomination Form 2013 2014 (EPBC Act) - Stiphodon Rutilaureus

Threatened Species Nomination Form

for amending the list of threatened species under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act)

for the 2013–2014 Assessment Period

(Assessment periods run from 1 October to 30 September)

Eligibility for Listing

1.1.NAME OF NOMINATED SPECIES (OR SUBSPECIES)

Scientific name:
Common name(s): / StiphodonrutilaureusWatson, 1996
Orange Cling Goby

1.2.NOMINATED CATEGORY

Note: if unsure about which category the species should be nominated for, refer to the indicative threshold criteria at Attachment B.
Vulnerable
Under criterion 2 this species should probably be listed as Critically endangered due to its very small area of occupancy. And indeed the very small population sizes and small distribution of adults within streams is of genuine concern. Under criterion 3 it should probably be listed as endangered. However, since I have now had some time to think about the rather unusual issues associated with amphidromoussicydiine gobies in Australia, I would like to offer some insights that may or may not influence the committee’s decision regarding the suitable listing category for this species. The adults are widespread in the Pacific and are consequently unlikely to disappear off the planet any time soon. However, the adult populations in Australia are small and fragmented as a function of limited available habitat (high rainfall, steep elevation areas, but only where entirely Australian freshwater fishes are essentially absent). The larvae of these species are probably extremely widespread but we have no way of knowing this at the current time (until some genetic research is funded).
Additionally, the criteria applied here are clearly used for terrestrial, marine and freshwater fauna (and flora) and as the committee will be well aware this means freshwater fishes by nature often have a small area of occupancy. Therefore taking into account the listing status and in some cases real status of certain unlisted, wholly freshwater fish species in Australia; I would suggest that Stiphodonrutilaureusmight actually be ‘vulnerable’. It faces serious threats with regard to some populations, but it is not facing anything like the problems of species such as the Red-finned Blue Eye, Murray Hardyhead or the new Pygmy Perch recently found in South Western Australia. Specifically, Stiphodonrutilaureus has a relatively large extent of occurrence that is a function of the highly dispersive nature of being an amphidromous fish, and this provides some buffer to extinction.

1.3.CRITERIA UNDER WHICH THE SPECIES IS ELIGIBLE FOR LISTING

Please mark the boxes that apply by clicking them with your mouse.
Criterion 2
Criterion 3
Criterion 4 / A2. Area of occupancy estimated to be less than 10 km2
and a) severely fragmented or known to exist at a limited location
Estimated total number of mature individuals is low (<2500) and
A2 a) and b) ii, iii, iv, v.
c) ii, iii, iv.
Number of mature individuals Low (<1000)

1.4.CURRENT LISTING CATEGORY

What category is the species currently listed in under the EPBC Act? (If you are nominating the species for delisting, please complete the nomination form for delisting).
Not Listed Extinct Extinct in the wild Critically Endangered
Endangered Vulnerable Conservation dependent / Not listed

1.5.2013–2014 CONSERVATION THEME:

There is no conservation theme for the 2013–2014 Assessment Period
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1.6.CONSERVATION STATUS

What is the species’ current conservation status under State/Territory Government legislation? Does the species have specific protection under other legislation or intergovernmental arrangements?
Stiphodonrutilaureusis not listed under state or federal legislation, although, it is currently being considered for listing as a no take (fisheries) species by the Queensland Government. The species is only recently known to occur in Australia (Ebner and Thuesen 2010) and its identity has been taxonomically and genetically confirmed by taxonomist Helen Larson and Philippe Keith since it was last nominated for EPBC listing (see Ebneret al. 2011).
Species Information

1.11.TAXONOMY

Provide any relevant detail on the species' taxonomy (e.g. naming authority, year and reference; synonyms; Family and Order) and whether or not it is conventionally accepted.
StiphodonrutilaureusWatson, 1996; Subfamily Sicydiinae; Family Gobiidae; Order Perciformes; conventionally accepted.

1.12.DESCRIPTION

Provide a description of the species, including size and/or weight, social structure and dispersion (e.g. solitary/ clumped/flocks), and give a brief description of its ecological role (e.g. is it a ‘keystone’ or ‘foundation’ species, or does it play a role in ecological processes such as seed dispersal or pollination).
Note: Information on the species’ geographic distribution should be included at Q.21–25, not here.
Stiphodonrutilaureus is a sexually dimorphic, small-bodied fish attaining a maximum total length of at least 42 mm. Males arewhite/cream with faint orange bars when not in display. They have an extended black dorsal filament. In full display the males are orange with blue cheeks; and can show black reticulation on the dorsal and caudal fins. Females are white or cream with closely aligned cherub blotches overlaying horizontal brown stripes. An orange tinge is often visible on the caudal peduncle unlike other females ofcongeneric species which do not show coloration. Females are gregarious often moving in small groups of up to twenty individuals. Males are solitary. The adult phase of the species function as bacterial/algal grazers in short coastal streams. In Australia, S. rutilaureusoccupies streams that comprise other amphidromous species including sicydiine gobies, and where the typical mainland fish community of large river catchments is absent or greatly reduced.
(Ebner and Thuesen 2010, Ebneret al. 2011,Thuesenet al. 2011).

1.13.BIOLOGY

Provide information on the species' biology, including its life cycle, generation length, reproductive and feeding characteristics and behaviours.
Note: Information on the species’ geographic distribution should be included at Q.21–25, and not here.
Stiphodonrutilaureus is amphidromous having a marine larval phase, and a freshwater juvenile and adult phase, including spawning and egg guarding in freshwater. Generation time is unknown but is likely in the order of 6 months to a few years. Larval duration of sicydiine gobies is generally in the order of 2-4 months. Females form small groups and move throughout shallow pools and runs in small and shallow streams (to depths of ~2 m) and occupy shallow water edges in deeper pools. This species occupies riffles, runs and shallow pools, and usually found on hard substratum in no or moderate flow. The species actively grazes during daylight hours on biofilms covering hard substratum. Males hold small territories at the head and foot of pools and in runs within cobble-boulder habitat. Males display (to other males and females) by extending fins and rapidly intensifying iridescent body coloration, and hovering with a jerking motion.
(Ebner and Thuesen 2010, Ebneret al. 2011)

1.14.HABITAT

Describe the species’ habitats and what role they play in the species' life cycle. Include whether or not the species is associated with, or if it relies on, a listed threatened ecological community or listed threatened species?
Note: Information on the species’ geographic distribution should be included at Q.21–25, and not here.
Male S. rutilaureus occupy cobble-boulder habitat often at the head or foot of a pool and in runs. They graze and defend small territories of a few square metres in area. Territories include platforms or boulders from which males display. Male-male contests are based on iridescent colour display. Presumably males court females at the entrance to an excavated burrow (situated in sand under rock) akin to Stiphodonsemoni and S. atratus but I have not witnessed this behaviour. Presumably males guard the eggs and post-hatch larvae drift downstream through creek mouths and to the sea as is the case with other members of the genus. These species are often found in steep, short, coastal streams that lack substantial if any estuary. Larvae require direct access to the ocean for survivorship and development. Little is known of the marine larval phase of sicydiines, except that they are capable of substantial time at sea (typically 2-4 months).Stiphodonrutilaureus overlap in distribution with other Stiphodonspp. in Australia; but this species typically has the most downstream distribution of the Stiphodon and is often found at the tidal limit.
(Ebner and Thuesen 2010, Ebneret al. 2011, Thuesenet al. 2011)
Transfer Information (for up-listing or down-listing of species)
Note: If the nomination is to transfer a species between categories please complete questions 15, 16 and 17. If the nomination is for a new listing please proceed to question 18. If the nomination is to delist the species, please use the delisting form.

1.15.REASON FOR THE NOMINATION FOR CATEGORY CHANGE

Please mark the boxes that apply by clicking them with your mouse.
What is the reason for the nomination:
Genuine change of status New Knowledge Mistake Other
Taxonomic change – ‘split’ newly described ‘lumped’ no longer valid

1.16.INITIAL LISTING

Describe the reasons for the species’ initial listing and if available the criteria under which it was formerly considered eligible

1.17.CHANGES IN SITUATION

With regard to the listing criteria, how have circumstances changed since the species was listed that now makes it eligible for listing in another category?
Population Size

1.18.NUMBERS

a.a.What is the total number of mature individuals? How was this figure derived?
b.b.Identify important populations necessary for the species’ long-term survival and recovery.

a. Numbers fluctuate within and among years but are typically less than 50 adult individuals in a catchment and often less than 10 in smaller catchments. The population size may reach a few hundred adults in some of the Cape Tribulation streams where the low gradient, lowland component of the stream is substantial (e.g. Emmagen Creek, Cooper Creek, Hutchinson creeks) but this is yet to be fully quantified. I currently estimate the number of adults based on current knowledge and assuming that un-surveyed suitable streams host similar numbers of individuals (e.g. on the Malbon Thompson Range) to be less than 1000 individuals in the Australian Wet Tropics. This is based on direct counts from a series of catchments (Ebner and Thuesen 2010, Ebneret al. 2011, Thuesenet al. 2011, XXXXXXXX and XXXXXXXX, unpubl. data).
b. Based on current knowledge, the Australian adult populations are greatest in the Cape Tribulation streams and streams of the Malbon-Thompson Range (XXXXXXXX and XXXXXXXX, unpubl. data). Small populations in tributaries of the lower Russell-Mulgrave River catchment (e.g. Fishery Creek) and along the Rex Highway (e.g. Ellis Beach region) and a tributary of Liverpool Creek, and at Russell Heads, appear to be small (typically less than 10 individuals) (XXXXXXXX pers. obs.). At this stage, the spatial and temporal connections between Australian and wider Indo-Pacific populations/metapopulations of Stiphodonrutilaureus are unknown.

1.19.POPULATION TREND

a.a.What is the population trend (PAST to CURRENT) for the entire species? Is the population trended increasing or decreasing, or is the population static? If possible, include a percentage change in population size over a 10 year or 3 generation period, whichever is the longer (for example, “this species has shownan 80% decline over 23 years, which is equal to 3 generations”). Please ensure you provide relevant data sources.
b.b.Is this trend likely to continue, or are there any data which indicate that there may be FUTURE changes in population size? Provide relevant data sources.
c.c.Does the species undergo extreme fluctuations in the number of mature individuals?

a. No long term relevant data; therefore trend unknown.
b. Trends are likely to have been relatively stable if Stiphodonrutilaureus was not widely distributed in urban (e.g. Cairns) and rural (e.g. sugar cane farm drains) streams and if Cape Tribulation has been the strong hold for this species in Australia during the post-European settlement period. Otherwise the trend was likely negative. The only relevant information is that a number of streams containing this species have human activity including water extraction occurring in current time. Water extraction, especially late in the dry season, in small streams, is concerning, since habitat is likely negatively affected by reduced stream flow and connectivity to the ocean, and complete dewatering of some streams.
c. In my experience this species is often present in Emmagen Creek, but at other locations its occurrence is patchy in time. It turns up as singletons at times and at other times is the most abundant Stiphodon in the stream (10s-50s).

1.20.PROBABILITY OF EXTINCTION IN THE WILD

Has the probability of the species’ extinction in the wild over a particular timeframe been quantified? If so, identify and explain the quantitative measures or models used to generate this probability.
The potential past, current or future extinction of this species has not been given serious research attention. At this stage the distribution and abundance of the species is being mapped in the Australian Wet Tropics, and effort is currently being put into determining at risk populations primarily in association with peri-urban development (XXXXXXXX and XXXXXXXX, unpubl. data).
Geographic Distribution

1.21.GLOBAL DISTRIBUTION

Describe the species' known or estimated current and past global distribution (include a map if available). Does the species exist within a threatened ecological community listed under the EPBC Act?
Stiphodonrutilaureusoccurs in Australia, Northern Papua New Guinea, Solomon Islands, Vanuatu, Bismarck Archipelago and New Caledonia(Keith et al. 2010, Ebneret al. 2011). The Australian populations likely represent a small fraction of global numbers of S. rutilaureus, due to a lack of suitable habitat (steep gradient coastal streams with an absence of non-amphidromous/continental fishes) in Australia. However, much of the potential range of this species remains to be surveyed.

1.22.EXTENT OF OCCURRENCE within Australia

NOTE: The distribution of the species within Australia is assessed in two ways, the EXTENT OF OCCURRENCE and the AREA OF OCCUPANCY. The two concepts are closely related, and often confused. Therefore, before you answer this question, please see the definitions and explanatory material in Attachment A.

a.a.What is the CURRENT extent of occurrence (in km2)? Explain how it was calculated and provide relevant data sources.
b.b.Has the extent of occurrence changed over time (PAST to CURRENT)? If so, provide evidence.
c.c.Is the extent of occurrence expected to decline in FUTURE? If so, provide evidence.
d.d.Does the species’ extent of occurrence undergo extreme fluctuations? If so, provide evidence.

a) The known extent of occurrence of S. rutilaureusspans the narrow coastal strip from Russell Heads in the central Wet Tropics to Emmagen Creek (Ebneret al. 2011). It will almost inevitably turn up in places where Stiphodonatratus is found and will likely have an extent of occurrence similar to that species. The species is typically found in less than a few hundred metres of a stream if present. Therefore the extent of occurrence of Stiphodonrutilaureusis in the order of 1000 km2.
b) Each year, I continue to discover very small populations of this species or an individual in marginal creeks but these discoveries have not increased the extent of the known occurrence of Stiphodonrutilaureus. To be fair, I am almost exclusively looking within the Wet Tropics.
c) I think the northern and southern extremes in known distribution of this species may expand with increased survey effort and might reduce with the advent of certain human impacts. The more important issue with this species relates to area of occupancy and populations near to Cairns where human impacts on streams are likely occurring currently or are likely to occur in the near future.
d) The extent of occurrence of the adult populations of this species probably fluctuates as a function of both itslife cycle (recruitment of the marine larval phase, lifespan of adults) andthe dynamics of available habitat (i.e. ephemeral streams and permanent streams (with intermittently opened stream mouths – i.e. opening to the sea)).

1.23.AREA OF OCCUPANCY
2.

a.a.What is the CURRENT area of occupancy (in km2)? Explain how it was calculated and provide relevant data sources.
b.b.Has the area of occupancy changed over time (PAST to CURRENT)? If so, provide evidence.
c.c.Is the area of occupancy expected to decline in FUTURE? If so, provide evidence.
d.d.Does the species’ area of occupancy undergo extreme fluctuations? If so, provide evidence.

a. The known area of occupancy of Stiphodonrutilaureusin Australia is certainly less than 10 km2 and probably less than 1 km2 depending on how it is calculated. The species is known from 12 creeks and is usually in a very short reach of 50-200 m of stream (i.e. a few pools)(with stream widths often 5-15 m). In the three creeks where S. rutilaureus distribution is known to be greatest in terms of stream length and area and where abundance is greatest (Noah, Emmagen and Oliver Creek) the sum total of stream length inhabited by this species is less than 5 km and therefore the area of stream that is occupied is less than 1 km2.
b. Unknown; possibly, in small coastal creeks in rural and urban landscapes, and where small holiday house/resorts utilize freshwater water. But this species is only recently recorded in Australia, so historical information is not available.
c. Yes. Increasing peri-urban development including water extraction and riparian zone clearing is likely to affect populations at Ellis Beach, in tributaries of the lower Russell-Mulgrave, Russell Heads, Yarrabahand potentially elsewhere, where small populations remain undetected.
d. Largely unknown. However, where streams have been revisited in some cases adult numbers appear to be relatively stable in certain pools/catchments but not in others. In some streams where adult S. rutilaureus have been observed they can be absent a few months or a year later, or vice versa (XXXXXXXX, unpubl, data).

1.24.PRECARIOUSNESS

a.a.Is the species' geographic distribution severely fragmented, or known to exist at a limited number of locations?
b.b.Is the area, extent and/or quality of the species' habitat in continuing decline (observed / inferred / projected)?
c.c.Is the number of locations or subpopulations in continuing decline (observed / inferred / projected)?
d.d.Are there extreme fluctuations in the number of locations or subpopulations of this species?

Please ensure that you provide evidence and appropriate references.