John Huisman

The Kimberley region is currently of great interest due to rapidly expanding development in oil and gas, fishing, aquaculture, and tourism. It is recognised as a relatively pristine area with a high diversity of habitats and species, but there is very little published information on the species present in the region. Museums and herbaria are the repositories of species diversity datasets and house specimens collected over many decades (1880s – present). The Western Australian Museum has led 8 major biodiversity expeditions (1988-2006) to the Kimberley region, but the species lists generated from these were mostly presented in unpublished reports and are not readily accessible to managers and researchers who are interested in the biological values of the region. We considered the Kimberley region to be defined by the following coordinates: SE: 19°S, 121° 34’ E; SW: 19°S, 118° 15’ E; NE: 12°S, 129° E; NW: 12°S, 121° E. This included the Kimberley coastline and the continental shelf edge atolls of the Sahul Shelf. We collated our institutions’ data on marine plants (seagrasses, mangroves and macroalgae), sponges, cnidaria (predominately hard corals), free living worms (predominately polychaetes), crustaceans (mainly decapod crustacean and barnacles), molluscs (predominately macromolluscs > 10 mm), echinoderms, brachiopods, ascidians, bryozoans and fishes and found > 30,000 specimen records representing ~6000 shallow water (<30 m) marine floral and faunal species now known from the area. This represents a minimum diversity estimate and much work remains to be done to identify and describe new species already housed in our collections, as well as to undertake further expeditions to adequately survey the biodiversity of this region. We have a series of papers in preparation for publication by the end of 2011, where we will provide a review of the species currently known from the Kimberley from our institutions databases with commentary on the diversity trends, collection and taxonomic gaps for our respective taxa. Here we present a summary of this research.

The marine biodiversity of the Kimberley is poorly known. The Western Australian Museum (WAM) commenced its multidisciplinary marine biodiversity survey program for this region in 1976, with further surveys occurring in the 1980s and 1990s. The vouchered specimens, published and unpublished reports of the WAM, and relevant collections housed in other museums and herbaria with a tropical interest, constitute the main biodiversity knowledge-base for this marine bioregion. In 2006, the WAM undertook a quantitative, multidisciplinary, marine survey of the north western atolls situated off the Kimberley continental shelf edge. This was later followed in 2008 by a biodiversity program, titled the Woodside Collection Project–Kimberley (Woodside 4), which will be finalised in 2011. The intent of this project was to examine the marine biodiversity of the Kimberley inshore region using both historic survey data (reports and collections) from the WAM and partner institutions, as well as new survey data from two field expeditions undertaken in 2009 to Adele Island and Montgomery Reef and in 2010 to Cassini Island and Long Reef. A new biodiversity program, the Woodside Collection Project–Kimberley (Woodside 5), is now underway with the intent of increasing the scope and resolution of the field data collected during the Woodside 4 field program. Woodside 5 (2011 – 2015) will include four separate surveys to targeted Kimberley coastal reefs and islands, and Browse Island on the mid-continental shelf, to provide latitudinal and longitudinal gradients of marine biodiversity data for the Kimberley Bioregion. Here we present an overview of this research to date.

Australia can lay claim to one of the richest and best-studied macroalgal floras in the world, but our understanding of this flora is geographically biased towards the southern and eastern coasts, the most populous regions that have also historically been home to the majority of active phycologists. In comparison, the north-west coast of Australia has been virtually neglected, a perhaps understandable situation given the region’s remoteness and significantly greater logistical difficulties, in addition to huge tidal flows, turbid water, and the presence of several top-level predators! Over the last 10 or so years the author and associates have been opportunistically collecting and intensively studying this marine flora, which has, in part, become considerably more accessible due to the resources boom presently underway in the region. These studies, the results of which will eventually be published in the ‘Algae of Australia’ series, have revealed a trove of undescribed taxa, as well as numerous poorly understood species previously known from limited historical collections, plus a large contingent of taxa that are common elements of the tropical Indo-West Pacific flora. Many of the collected specimens have also been incorporated into ancillary DNA-based phylogenetic studies, thereby enabling a more global perspective of the north-western Australian flora. This seminar will include an overview of the broader project, plus a more detailed examination of some of the more interesting taxa that have emerged from the studies.

The green macroalgal genus Codium (Chlorophyta, Codiales) is one of the most diverse genera in the world, comprising approximately 125 globally distributed species. Taxonomic studies on the Codium species found on the Western Australian coastline are mostly lacking. The genus displays a variety of morphologies, from globular to frond-like to erect and dichotomously branching. One subspecies, C. fragile subspecies fragile (Suringar) Hariot, is one of the most invasive seaweeds in the world, and is a major ecological and economic threat to the invaded habitat. It is a somewhat cryptic subspecies as it has a global distribution that overlaps morphologically similar native subspecies. This invasive alga was recently discovered in Princess Royal Harbour, Albany, Western Australia. Seventeen C. fragile ssp. fragile plants were collected from the Albany tug pen, and housed in a holding tank at 21° C. Two individual thalli were cultured at 20°C, 25°C and 28°C to determine their tolerance to increased water temperatures, and to gain insight into the subspecies potential spread in W.A. Culturing results indicate that at increased temperatures (> 25°C), the growth of Codium fragile ssp. fragile is strongly inhibited, indicating that its potential spread in W.A. may be temperature limited. To prepare a taxonomic account of the species occurring in W.A., specimens of Codium housed at the W.A. Herbarium (PERTH) were examined. Small portions of plants were removed and rehydrated in freshwater, and the utricles were excised and observed under a microscope to obtain anatomical measurements. On the basis of the PERTH collections, nineteen species of Codium occur on the coast of W.A. Thirteen of these have been documented previously, whilst five are, for the first time, described in detail based on W.A. specimens: C. arabicum Kützing, C. dwarkense Børgesen, C. fragile subspecies fragile (Suringar) Hariot, C. geppiorum O.C. Schmidt and C. platyclados R. Jones & Kraft. One species, from Nornalup Inlet on the south coast, appears to represent a new species, based on its morphology and analyses of its anatomical details. For all nineteen species, morphological and anatomical descriptions and illustrations are given, in addition to information on their local and worldwide distribution and habitat.

A genus dominating the brown algal flora of most tropical areas, Sargassum C.Agardh, has long been a challenge for taxonomists in terms of species delimitation and sub-generic assignment. In Australia, where more than a quarter of all species have been recorded, Sargassum species provide habitat, structure and food for a wide range of animals and plants. Thalli are usually large and brown, and physically differentiated into stem, leaves, vesicles and reproductive branches. Despite this suite of features available for identification, the task of taxonomic assignment is complicated by within-species variation due to morphological plasticity, seasonality and developmental forms. In this study, Sargassum species sampled from Esperance, W.A. to the Kimberley, W.A. over 3 years were sequenced for the nuclear ITS-2, mitochondrial cox3 and chloroplast rbcL-S spacer regions. The three current Australian subgenera are supported by this study, Phyllotrichia J.Agardh, Arthophycus J.Agardh and Sargassum J.Agardh and a fourth is proposed. Fifteen genetic species were found, including two new species, from 51originally listed from WA shores. Many of the original records are now recognised as synonymies or misidentifications.In the subgenus Phyllotrichia, all previous species remain current except Sargassum peronii C.Agardh which is now synonymised with S. decurrens (R.Brown ex Turner) C.Agardh. In subgenus Arthrophycus, only two distinct genetic species are obvious from all Australian collections, necessitating a clearer revision of the subgenus. A North West species, most closely conforming to the description of Carpophyllum nothum Grunow, which has long been synonymized with Cystoseira trinodis (Forsskål) C.Agardh, will now be moved to Sargassum. It shares morphological similarity to both subgenus Arthrophycus and Sargassum and is a clear intermediate between the two subgenera, an observation supported by molecular data. In Subgenus Sargassum at least 10 species appear distinct with many new synonymies proposed or validated from recent work on the group. This study further shows the usefulness of molecular techniques in taxonomic delineation of morphologically plastic species, and provides greater insight into the true species richness of Sargassum, an ecologically and economically important genus of macroalgae.

The red algal order Halymeniales contains a relatively high percentage of sponge-associated taxa. These species are predominantly classified in two genera, Thamnoclonium and Codiophyllum (and to a lesser extent, Carpopeltis), and are chiefly distributed in temperate waters along the South African and Australian coasts. Three rare species of Thamnoclonium (T. tissotii, T. treubii, and T. procumbens), however, were originally described by Weber-van Bosse from tropical localities in Indonesia, the Philippines, and northern Australia. These formed her new Thamnoclonium sect. Nematophorae and differ from typical Thamnoclonium in having a pseudoparenchymatous medulla in vegetative tissue and in the production of moniliform chains of cells from the cortex. Recent collections of T. tissotii from Western Australia included tetrasporangial and cystocarpic specimens, the latter previously unrecorded for the section. Phylogenetic analyses of rbcL sequence data generated from these and other specimens revealed that the genus Thamnoclonium is presently polyphyletic. Although the phylogenetic tree was not completely resolved, sponge-algal associations in the Halymeniales seem to have evolved independently at least four times. Specimens of T. tissotii formed a sister relationship with Codiophyllum. Thus, both morphological and DNA sequence analyses support the segregation of Thamnoclonium sect. Nematophorae as a new genus, for which the name Spongophloea is proposed, in recognition of its seemingly obligate relationship with the sponge that coats the thallus surface.