Marine cyanobacterial, algal and plant biodiversity in southeast Queensland: knowledge base, issues and future research directions

2008·13.7 MB·English

by  Julie A Phillips

Marine cyanobacterlal, algal and plant biodiversity in
southeast Queensland: knowledge base, issues and
future research directions
Julie A. PHILLIPS
Eco Algae Research Pty Ltd, 74 Coronation St, Bardon, Qld 4065, Australia. Email:
[email protected]
Citation: Phillips, J.A. 2008 12 01. Marine cyanobacterial, algal and plant biodiversity in southeast
Queensland: knowledge base, issues and future research directions. In, Davie, P.J.F. & Phillips,
J.A. (Eds), Proceedings of the Thirteenth International Marine Biological Workshop, The Marine
Fauna and Flora of Moreton Bay, Queensland. Memoirs of the Queensland Museum — Nature
54(1): 421-443. Brisbane. ISSN 0079-8835.
ABSTRACT
Cyanobacteria, algae, seagrasses and mangroves contribute significantly to marine
ecosystem function in their roles as primary producers underpinning marine food webs,
as ‘ecosystem engineers’ providing habitat, and in modulating global biogeochemical
cycles and stabilising shorelines. Species-level knowledge for these organisms in
southeast Queensland varies greatly, with the relatively few seagrass and mangrove
species well studied compared to the underdescribed and undersampled algae and
cyanobacteria. Algal/cyanobacterial species richness for the region is high but data on
biodiversity patterns of these organisms and the ecological processes that cause,
maintain and regulate these patterns are dismally incomplete. There are no comprehensive
algal/cyanobacterial floras for eastern Australia, ensuring that numerous species are
difficult to identity with certainty and thus can not be effectively treated in scientific
studies. Accurate identification and knowledge of algal/cyanobacterial biology and
ecology at the species level are essential prerequisites underpinning biotic surveys,
biomonitoring programs and management strategies for algal/cyanobacterial blooms,
exotic species, climate change, rare and threatened species and marine protected
areas. Research programs documenting species composition and abundance in marine
communities and the ecological and geographical distribution of species are urgently
required to provide rigorously-collected data on the ecologicaliy-important cyanobacteria
and algae in southeast Qld in order to provide the scientific basis underpinning marine
environmental management and marine conservation initiatives, particularly biodiversity
conservation. The inability to identify species seriously imperils efforts directed towards
arresting the irreversible loss of biodiversity. (cid:9633) cyanobacteria, algae, seagrasses, mangroves,
biodiversity, consen/af/on, Australia,
Although widely acknowledged to exist at composition generally plays a crucial role in
multiple levels of biological organisation ranging ecosystem dynamics and function (Dayton 1972;
from genes to ecosystems, it is understanding Knowlton & Jackson 1994; Jones et al 1997;
biodiversity at the species level that plays a Tilman 1999; Loreau et al. 2001; Altieri et al.
central role in our efforts to conserve species 2007). Species drive ecological processes which
and the habitats, ecosystems and biomes in which will undergo functional shifts when sets of
species live (May 1995; National Research Coun¬ species are lost or replaced by other species
cil 1995; Bianchi & Morri 2000; Mikkelsen & with differing traits and interactions. Biological
Cracraft 2001; Mace 2004). Biodiversity results impoverishment through species loss reduces
from the diversification of species. Species the resilience of ecosystems to environmental
Memoirs of the Queensland Museum — Nature • 2008 • 54(1) • www.qm.qld.gov.au 427
Phillips
change, an important concept underpinning the terrestrial equivalents (Kaufman 1988; Murphy
endeavours of conservation biology which & Duffus 1996; Bianchi & Morri 2000; Kochin &
aims to protect not only 'iconic species' but also Levin 2003; Boudouresque et al. 2005), resulting
a wide range of species, including many poorly in fragmentary historical data sets on species
known and often overlooked species (Murphy composition and abundances in marine com¬
& Duffus 1996; Mikkelsen & Cracraft 2001; munities. Also of great concern is the marked
Clarke & May 2002, Roberts et al. 2003; lack of recent reliable data on changes in
Kenworthy et al. 2006), many of which contribute species composition and abundances in many
greatly to the sustainability of life on Earth marine systems (Boudouresque et al. 1995;
(Corliss 2002). Bianchi & Morri 2000; Hiscock et al. 2003).
Surprisingly, the great majority of species on Little is known of the scale and rate of species
Earth are unknown to science (Raven & Wilson loss resulting from anthropogenic impacts on
1992; May 1995; Wilson 2000, 2002; Mace 2004; marine ecosystems (Kaufman 1988; Carlton et
Crisci 2006; Hodkinson & Parnell 2006). Between al. 1991, Carlton 1993; Norse 1993,1995; Roberts
1.5 and 1.8 million species have been described, & Hawkins 1999). Known marine extinctions
with conservative estimates of 7 to 15 million were limited to relatively few megavertebrate
species yet to be discovered. Thousands of spe¬ species (Norse 1993; Vermeij 1993), reflecting
cies, both known and unknown, are threatened the difficulty in detecting extinctions of incon¬
by an accelerating rate of extinction, correlated spicuous marine species. Furthermore, the full
to an increasing human population. Loss of two- extent of this irreversible biodiversity loss may
thirds of all species on Earth is predicted by the never be realised because many marine species
end of this centur\' (Raven 2002 and references may have been exterminated before discovery
therein). Unfortunately, our ability to devise (Roberts & Hawkins 1999; Dayton 2003). The
science-based action plans to save species from first documented marine invertebrate neoex¬
extinction is severely limited by the fragmented tinction (the eelgrass limpet) was reported 50
knowledge base in which < 1% of described years after the event (Carlton et al. 1991). Sub¬
species are estimated to have been studied sequently, several more marine invertebrate
beyond the meagre essentials of morphology, neoextinctions have been reported (Carlton 1993;
habitat preference and geographical location Roberts & Hawkins 1999). Similarly, data on
(Wilson 2000; Crisci 2006). Biodiversity loss is algal extinctions is also sparse, with Vanvoorstia
irreversible, and unfortunately our ignorance bewiettiam Harvey last recorded for Port Jackson
of the biota ensures that we are ill-equipped to nearly 150 years ago the only alga regarded as
both understand tlie significance of its loss, and extinct (Millar 2003).
protect against it (Clarke & May 2002; Dayton The extent of biodiversity encompassed by
2003). cyanobacteria, algae, mangroves and seagrasses
The pressing need for marine conservation is enormous, representing five of the six King¬
was first recognised by Kaufman (1988) who doms of Life (Keeling 2004; Palmer et al. 2004)
challenged the then widely accepted scientific (Table 1). Although these phototrophic organisms
and popular belief that marine ecosystems were are commonly referred to as 'marine plants',
beyond the deleterious impacts of the human only the Chlorophyta (green algae) which are
race. We now know that marine ecosystems the ancestors of the land plants, Rhodophyta
have been have been dramatically degraded (red algae), mangroves and seagrasses belong
(Ray & Crassle 1991; Norse 1995; Dayton 2003) to the Plant Kingdom. Other algal phyla are
and continue to be threatened by the over- assigned to three other Kingdoms with the pro¬
exploitation of natural resources, increasing karyotic Cyanobacteria in the fifth Kingdom.
habitat alteration and degradation, worsening These differing evolutionary histories have
eutrophication, introduction of alien species and profound effects on the biology, physiology
the impacts of global climate change (Norse and ecology of organisms which must be
1993; National Research Council 1995). Unfor¬ understood before effective management and
tunately, marine ecosystems and marine bio¬ conservation initiatives can be devised. Cyano¬
diversity have been far less studied than their bacteria and algae evolved in and developed
428 Memoirs of the Queensland Museum — Nature • 2008 • 54(1)
Marine cyanobacterial, algal and plant biodiversity in SE Queensland
Table 1. Species richness of marine phototrophs. Based on Brodie & Zuccarello 2006 Williams & Reid 2006
Saenger 2002 Den Hartog & Kuo 2006 Phillips 1998a
Estimated described (total Known species
Kingdom Taxa
species) worldwide richness in SE Qld
Bacteria Cyanobacteria 2 000 (?) 1-2 7
Excavates Euglenophyta 9591-2 7
Alveolates Dinophyta (dinoflagellates) 1240 (11 000) i'2 7
Phaeophyta (brown algae) 1718 (2000) ^'2 515
Chrysophyta (golden algae) 2 400 (5 000) ^'2 7
Chromista Bacillariophyta (diatoms) 6423 (200 000) ^'2 7
Haptophyta (coccolithophorids) 510 (2000) i'2 7
Cryptophyta (cryptomonads) 85 (1200) i'2 7
Chlorophyta (green algae) 3215 (20 000) i'2 65 5
Rhodophyta (red algae) 5781 (20 000) 1-2 1615
Primoplantae
Mangroves 84 3 8
Seagrasses 64 4 8
the adaptations necessary for life in aquatic red algae, an ancient lineage dating back to the
environments. By contrast, mangroves and sea- oldest (1200 million years old) resolvable eukary¬
grasses which colonised the marine environ¬ otic fossil Bangio}7W}‘p]m pubescens Butterfield
ment during the late Cretaceous/ early Tertiary (2000) are the most speciose macroalgal phylum,
have retained most features characteristic of with approximately 25% of species described
their land plant ancestors (Saenger 2002; Kuo & by science.
Den Hartog 2006). Seagrasses are unique, being Tliis paper establishes the crucial role that
the only submarine flowering plants on Earth. marine phototrophs play in marine ecosystems
Relatively few species of flowering plants (only and reviews the species-level knowledge base
seagrasses and mangroves) have adapted to life for these organisms in southeast Queensland, a
in the harsh environment of the land/sea inter¬ region defined geographically from Noosa to
face (Table 1). Coolangatta in the tropical to temperate biogeo¬
graphic overlap zone on the Australian east
Approximately 350,000 algal species are estim¬
coast For this region, species of marine cyano¬
ated to occur on Earth, similar to the species
bacteria and algae are poorly known whereas
richness for higher plants (World Conservation
seagrass and mangrove species are compara¬
Monitoring Centre 1992; Williams & Reid 2006; tively well known. The importance of detailed
Brodie & Zuccarello 2006). Algal species are taxonomic, ecological and biogeographic data
generally poorly known, with fewer described on the marine phototrophic species is discussed
species compared to higher plant species. in relation to biotic surveys, biomonitoring, algal
Species richness and the proportion of described blooms, invasive exotic species, rare and threat¬
to undescribed species varies among the algal ened species and marine protected areas. Future
phyla (Table 1). The diatoms, whose first repre¬ research directions are outlined to collect much
sentatives appeared in the fossil record circa needed data on species composition, abundance,
190 million years ago (Sims et ai 2006), are both ecological and geographical distribution pat¬
the most speciose and poorly known phylum, terns of cyanobacterial and algal species in marine
with only approximately 4% of species des¬ communities of SE Qld at varying spatial and
cribed. The sister group of the diatoms, the temporal scales, highlighting the pressing need
Bolidiophyceae, comprises 3-5 species of small for rigorously-collected detailed data at the
flagellates discovered during the last decade species level to underpin marine management
(Guillou et al. 1999). Among the seaweeds, the and conservation planning.
Memoirs of the Queensland Museum — Nature • 2008 • 54(1) 429
Phillips
SIGNIFICANCE OF MARINE seagrass primary production (Kitting et al.
PHOTOTROPHS 1984; Daehnick et al. 1992; Mateo ct al. 2006),
Phototrophs are of great ecological, conser¬ with a large proportion (20-62%) of epiphyte
vation and economic importance in marine eco¬ primary production consumed by herbivores
systems, providing a wide range of essential (Klumpp et al. 1992). Mangrove and seagrass
'ecosystem services' (Myers 1996; Costanza et communities are highly productive, but most
al. 1997) that sustain ecosystem function, the production enters detrital food webs (Newel et
human race, and the health of our planet. Con¬ al. 1995, Marguillier ct al. 1997; Valentine &
sidering only two ecosystem services, estuarine Duffy 2006), with low proportions (10-30%) of
algal/seagrass beds are valuated at $US19,004 seagrass production removed by herbivores
ha-^ yeaH for the recycling of nutrients and raw (Mateo et al. 2006; Valentine & Duffy 2006).
materials (Costanza et al. 1997) and $US30,000
2. HABITAT HETEROGENEITY
ha-^ year-i in fishery production (Virnstein &
Mangrove, seagrass, macroalgal and cyano¬
Morris 2000). Loss of vital ecosystem services
bacterial species are 'foundation species' (Dayton
from estuaries degraded by coastal develop¬
1972,1975) or 'ecosystem engineers' (Jones et al.
ment and pollution costs the US more than $200
1994), structuring the local environment to either
million year^ in lost commercial fish produc¬
positively or negatively affect the survival of
tion (Myers 1996). Marine phototrophs contrib¬
other species in the community. Foundation
ute significantly to numerous ecosystem services
species increase habitat heterogeneity and supply
including primary production, habitat hetero¬
predator protection for many organisms, inclu¬
geneity, biogeochemical cycling, biostabilisation
ding juvenile stages of commercially-exploited
of sediments, and are also useful as environmental
fishery species (Brawley & Adey 1981; Kitting
indicators and sources of marine natural
et al. 1984; Poore 1994; Haywood et al. 1995;
products.
Heck et al. 2003; Gillanders 2006). Seagrass,
1. PRIMARY PRODUCTION AND ENERGY FLOW IN mangrove and kelp communities are widely
MARINE FOOD WEBS
acknowledged as foundation species but many
As primary producers, cyanobacteria, algae,
other algal/cyanobacterial species also fulfil
seagrasses and mangroves underpin marine food
this important ecological role. For example, the
webs in a biosphere where total global marine
green alga Halitueda and coralline red algae are
and terrestrial net primary production are
'ecosystem engineers' on coral reefs, with CO3
similar (Field et al. 1998). Algae are the major
sediments derived from these calcareous algae
marine primary producers in all marine eco¬
being quantitatively more important for coral
systems (Mann, 1973, 1988; Field et al. 1998).
reef construction than CO sediments from
Phytoplankton support oceanic and coastal food 3
corals (Stoddart 1969; Milliman 1974, Hillis-
webs (Mallin & Paerl 1994; Deegan & Garritt
Colinvaux 1980; Drew 1983; Rees el al. 2007).
1997; Falkowski et al. 1998; Calbet & Landry
Encrusting coralline red algae provide further
2004). Algal turfs and symbiotic dinoflagellates
ecosystem services by retarding reef erosion
in corals contribute about 50% and 30% of the
from high-energ}^ oceanic waves by overgrowing,
primary production of healthy coral reef eco¬
cementing and stabilising calcareous sediments
systems respectively (Adey & Steneck 1985;
on outer reef rims (Womersley & Bailey 1969;
Klumpp & McKinnon 1989; Adey 1998), with
Littler & Doty 1975; Littler & Littler 1984; Adey
60-100% of turf algal production consumed by
1998).
the intense grazing pressure of herbivores (Adey
& Steneck 1985; Adey & Goertemiller 1987; 3. GLOBAL BIOGEOCHEMICAL CYCLES
Klumpp & McKinnon 1989). Cyanobacterial Marine phototrophs are important in the global
and/or algal mats/biofilms adhering to muddy/ carbon cycle, removing CO from atmospheric
2
sandy substrata are often the dominant primary and oceanic sinks and sequestering some of C
producers in estuarine ecosystems (Underwood fixed by phytoplankton by sedimentation in the
& Kromkamp 1999), Algal primary production ocean depths (Raven & Falkowski 1999) and in
(benthic microalgae, epiphytes, phytoplankton) CO sediments in Halimeda biotherms on coral
3
in seagrasses communities often far exceeds reefs (Rees et al. 2007). Phytoplankton,
430 Memoirs of the Queensland Museum — Nature • 2008 • 54(1)
Marine cyanobacterial, algal and plant biodiversity in SE Queensland
particularly species forming massive oceanic
6. NATURAL PRODUCTS
blooms, and macroalgae play a central role in
Marine algae are used extensively for human
the global sulphur cycle, being the major source
and animal food and in industrial and medical
of atmospheric dimethyl sulphide, a compound
products (Borowitzka & Borowitzka 1988;
which forms cloud condensation nuclei and
Lembi & Waaland 1988). In 2004, mariculture of
cloud droplets to bioregulate climate by
Laminaria japonica (kombu), Porpin/ra (nori), and
influencing the Earth's radiation budget
Undaria pinnatifida (wakame) produced 4.5,1.4
(Charlson et aL 1987; Bates et al. 1992; Malin &
and 2.5 million metric tons valued at 2,75,1.34
Kirst 1997). Nitrogen-fixing cyanobacterial
and 1.02 billion US$ respectively (FAO 2006),
species are important in the global nitrogen
being used primarily for human food. The red
cycle, potentially adding tons of N to marine
alga Porfdn/ra is used as the outer wrapper in
ecosystems during blooms (Capone et al. 1997).
sushi. Hydrocolloids extracted from excess mari-
Algal and cyanobacterial mats are important
cultured and wild-collected kelps (alginates)
in the regulation of the benthic-pelagic nutrient
and red algae (agar, carrageenans) are used in
cycling loops (Lapointe & O'Connell 1989,
tlie food processing industries. Antifouling agents
La very & McComb 1991, Thybo-Christesen et
added to marine paints have been extracted
al. 1993, Valiela ctai 1997, SundbackcM/. 2003).
from algae (de Nuys & Steinberg 1999). Marine
4. BIOSTABILISATION OF SEDIMENTS algae exhibiting antibacterial, agglutinin, anti¬
Mangroves, seagrasses, algal and cyanobac¬ fungal, anticoagulant, antitumor and antiviral
terial mats stabilise unconsolidated sediments activity are potential sources of new bioactive
by reducing the erosive capability of seawater chemicals, important for supplying new drugs
passing through/over these communities to combat resistant infectious and newly emer¬
(Yallopc/n/. 1994; Underwood 1997; Paterson & gent diseases.
Black 1999; Gacia & Duarte 2001; Saenger 2002;
Kenworthy etal. 2006). Decreasing water velocity KNOWLEDGE BASE
increases sedimentation of particulate matter, The biodiversity of mangrove and seagrass
improving water clarity and reducing water species of SE Queensland is well known. Eight
column nutrient levels. Mangrove canopies also mangrove species occur in sheltered bays and
reduce wind velocities, thus protecting terres¬ estuaries in the region (Hegerl & Timmins 1973;
trial vegetation and buildings during storms Shine et al. 1973; Dowling 1979, 1986; Davie
and cyclones. 1984,1992; Hyland Bulter 1988), all of which
5. INDICATORS OF ENVIRONMENTAL HEALTH are widely distributed in the tropical Indo-West
Decreases in seagrass depth ranges or in the Pacific. In SE Qld, Avicennia marina (Forssk.)
areal extent of seagrass communities are used Vierh. is the most ecologically widespread and
to monitor seagrass ecosystem health (Dennison abundant species with Rhizoplwra st\/losa Griff,
& Abal 1999). Algal species respond quickly to and Aegiceras corniculatiim (L.) Blanco also com¬
environmental change with changes in species mon. Lumnitzera racemosa Willd. and Excoecaria
composition and abundance. Eutrophication agalloclia L. reach their southern distribution
usually results in decreased algal species rich¬ limit in Moreton Bay (Macnae 1966). The
ness, changes in species composition and com¬ mangrove fern Acrostichium speciosum Willd. is
munity complexity (Littler & Murray 1975; found in tidal creeks and swamps in the region.
Lapointe & O'Connell 1989; Brown et al. 1990; Hyland & Bulter (1988) surveyed the species
Hardy et al. 1993, Middelboe & Sand-Jensen composition and distribution of mangrove com¬
2000). Algal species intolerant to fluctuating munities in SE Qld, which are best developed
salinities, elevated nutrient levels and toxic sub¬ on the muddy deltas of the Logan, Pimpama
stances are replaced by fewer tolerant species and Coomera Rivers in southern Moreton Bay.
which dramatically increase in abundance. These communities are unique being the largest
Sensitivity of early developmental stages of area of mangroves on the east Australian coast
algal species to low concentrations of toxicants south of the Wet Tropics region.
is used by bioassays to assess water quality Eight species of seagrasses (including Halopddla
(Reed et al. 1994; Kevekordes 2001). minor (Zoll.) Hartog, this volume) inliabit the
Memoirs of the Queensland Museum — Nature • 2008 • 54(1) 431
Phillips
sheltered estuaries and bays of SE Qld (Young Caloundra to Jumpinpin over the last 100 years
& Kirkman 1975; Kirkman 1975; Poiner 1985; (Phillips 1998a). While the BRI macroalgal
Hyland et al. 1989; Poiner et al. 1992; Dennison collection is extremely valuable and indicates
& Abal 1999; McLennan &: Sumpton 2005). high macroalgal species richness for this poorly
With the exception of Zostera capricorni Asch. studied region, limitations of these data ensure
which is geographically limited to eastern that they are inadequate for the purposes of
Australia, New Guinea and New Zealand, the environmental management and conservation
other species are widely distributed in the tropi¬ planning for the following reasons:
cal Indo-West Pacific. Moreton Bay is the southern 1. Specimens have been updated to currently
distribution limit of Sx/ringodium isoetifoliiim accepted names, but with the exception of some
(Asch.) Dandy, Ci/modocea sernilata (R.Br.) brown algal species (Phillips & Price 1997),
Asch. ex Magnus and Halodule uninervis many species identifications have generally not
(Forssk.) Asch. (Poiner & Peterkin 1995). Zostera been verified (though they could be with
capricorni is the most abundant and widespread further taxonomic study). Thus the collection
species in the region, frequently growing as mono- undoubtedly includes misidentified species,
specific meadows. The clear oceanic-influenced species whose concepts have changed following
waters of eastern Moreton Bay support the most subsequent taxonomic revision, and species
species-rich and abundant seagrass communities new to science. It is vital that herbarium
in the region, unlike western Moreton Bay where specimens bear the correct species name as this
high turbidit}^ limits seagrass growth (Young & establishes a species' biological identity and its
Kirkman, 1975; Poiner, 1985; Abal & Dennison, ecological role. As Gotelli (2004) emphasises,
1996). correct identifications are crucial for reliable
Our knowledge of the marine algal and cyano- community analyses.
bacterial species of SE Qld is dismally incom¬ 2. Specimens result from opportunistic and
plete, these species having received minimal sporadic collecting over the last 100 years and
taxonomic and ecological study. There are no not from surveys using standardised sampling
comprehensive marine algal/cyanobacterial floras effort. Tlie number of species recorded at a
for the Australian east coast, and this represents locality is related to sampling effort (Womersley
a major impediment to including these organ¬ & Bailey 1970; Edgar et at. 1997; Middelboe et al.
isms in ecological surveys, documenting bio¬ 1997; Bianchi & Morri 2000; Gotelli 2004).
diversity patterns or devising strategies for Therefore, comparisons of macroalgal species
marine environmental management and conser¬ richness at different localities, or documenting
vation plaiining. Algal and cyanobacteria 1 species macroalgal distribution patterns based on a
are common on rocky shores, deep rocky reefs, highly variable sampling effort, are scientifically
sand and mud flats, and in seagrass and flawed. The most species rich localities,
mangrove communities in SE Qld, but with the Caloundra (103 species) and Redcliffe (109
lack of adequate sampling or study, the identity species), were sampled on many occasions and
of many local species may not be accurately cannot be compared with sites sampled only
known, and species richness and endemism once to record <10 species.
may be underestimated. 3. Specimens were not collected as part of a
Knowledge of the marine macroalgal (Chloro- quantitative sampling program using standard
phyta, Phaeophyta, Rhodophyta) species of SE ecological techniques and consequently there is
Qld is largely limited to eight scientific papers no data on species abundance, community struc¬
(Askenasy 1894; Johnston 1917; Cribb 1979; ture or on the spatial and temporal variability
Saenger 1991; Phillips 1997b, 1998a, Phillips, in macroalgal communities on annual, decadal
2002; Phillips & Price 1997) and references to or longer time scales. There is also little indi¬
various species scattered throughout the scien¬ cation whether small, inconspicuous, subtidal,
tific literature. Based on vouchered herbarium or seasonal macroalgal species were included
specimens at the Queensland Herbarium (BRI), in the collections. Furthermore, locality data
approx. 275 species have been collected from from the many drift specimens is unreliable.
432 Memoirs of the Queensland Museum — Nature • 2008 • 54(1)
Marine cyanobacterial, algal and plant biodiversity in SE Queensland
apparent from the Noosa collection of the tem¬
flood data collected during both a narrow
perate brown alga Honuosira banksii (Turner)
sampling window and atypical prevailing
Decne., which has a northern geographical
envirorunental conditions. Phytoplankton blooms
distribution limit in northern NSW.
regularly occur in Moreton Bay but have not
Current knowledge indicates that macroalgal been documented in the scientific literature.
species with tropical affinities predominate in The surf-zone diatom Anaulus australis Drebes
Moreton Bay (65%), with cool temperate species et Schultz is recorded as blooming at Main
ranging from southern Australia (15.2%) and Beach, Southport (Hewson et al, 2001) and more
species with cosmopolitan distribution patterns generally along SE Qld coasts (pers. observ.),
(20.8%) also contributing to the flora (Phillips
exception of L\/ngbi/a majuscula
1998a). In SE Qld, macroalgal communities are
(Dillwyn) Har\\ and Trichodesmium, little is
best developed on rocky substrata on the
known of the marine cyanobacteria 1 species of
Redcliffe Peninsula, on rocky headlands of the
SEQld. Cribb (1979) recorded 13c\^anobacterial
wave swept coasts (pers. observ.) and on deep
species from salt marshes and mangroves in
water rocky outcrops east of Stradbroke and
Moreton Bay, but this number gives little
Moreton Islands (Stevens & Connolly 2005). In
indication of cyanobacteria! species richness for
sheltered areas with muddy/sandy substrata, the region. Abundant thick mats of Microcoleus
macroalgal species grow on firm substrata such chthouoplastcs Thur. ex Gomont, a species not
as mollusc shells, rocks and pebbles and as previously recorded from Moreton Bay, are
epiphytes on mangrove roots and seagrasses. reported from areas of mangrove dieback at
Little is known of the biodiversity of marine Whyte Island (Phillips & Kevekordes 2008).
phytoplankton of SE Qld despite these orga¬ Species richness or communitv structure of
nisms fixing approx 60% of the total primary the microphytobenthos of Moreton Bay which
production of the Moreton Bay ecosystem (Eyre is estimated to fix 85,000 t C year’ (Eyre &
& McKee 2002). Currently, there is no phyto¬ McKee 2001) has not been documented. Micro¬
plankton species list and little data on the ecology phytobenthos typically occurs as either microbial
of phytoplankton communities in SE Qld, but mats or biofilms on sandy/muddy substrata
species richness is expected to far exceed that of (Yallop et al. 1994). Stratified microbial mats are
the macroalgae. Phytoplankon communities often mm thick, and are composed of three
are generally spatially variable, evident from layers: an upper-most diatom mucopolysac¬
domination by either tropical Coral Sea dino- charide layer, a species-rich diatom midlayer,
flagellates particularly Ccratiuw spp. or the and a lower-most layer of filamentous
diatom Paralia sulcata (Ehrenberg) Cleve (as cyanobacteria, often Microcoteus chtJwuoplastes,
Melosira sulcata (Ehrenberg) Cleve) and the although species of Oscillatoria, Spirulhia, Meris-
dinoflagellate Dinopln/sis caudata Saville-Kent uiopedia, Gloeothcce, Lyiigbya and Phormidiutn
in the oceanic and estuarine sections of Moreton may also be present. Biofilms are composed of
Bay respectively (Ferguson-Wood 1964). Phyto¬ many diatom species and diatom mucopoly¬
plankton communities arc generally composed saccharide and tend to be transient, relatively
of many different algal phyla. This is typified thin (100 |jm) and unstratified. Microphyto-
by a winter flood-influenced community in benthic communities typically comprises 50 to
western Moreton Bay that comprised 145 species, 100 species at a locality (Underwood 1997,2002;
including diatoms (81 species), dinoflagellates Underwood et at. 1998).
(54 species) and 1-2 species each of crypto-
phytes, chrysophytes, euglenophytes, prasino- ISSUES
phytes and rhapidophytes (Heil cf al. 1998a, b). NEED FOR TAXONOMY
The flood would be expected to shift phyto¬ Taxonomic studies are urgently required to
plankton species composition to more curyha- fully document biodiversity of marine cyano¬
line species and consequently the lack of baseline bacteria and algae of SE Qld by defining
monitoring data on species composition and undescribed, under-described and inaccurately
abundance precludes interpretations of the described species and compiling this data into
Memoirs of the Queensland Museum — Nature • 2008 • 54(1) 433
Phillips
floras/field guides for the region. Taxonomy is communities (see Knowlton & Jackson 1994 for
the science that not only discovers and review)) but also marine species generally have
documents biodiversity (Wilson 2000,2002) but been erroneously thought to be common and
also provides the biological reference system widely distributed, two features thought to
for recognising and naming species. The protect species from extinction (Roberts &
southern Australian marine macroalgal flora Hawkins 1999). Many cryptic marine macroalgal
has been well documented, most recently in the species with restricted geographical ranges have
six volumes of the 'Marine Benthic Flora of been identified, necessitating the description of
Southern Australia' (Womersley 1984, 1987, new genera (Phillips 1997a; Nelson et al. 2006)
1994,1996,1998,2003) which has enabled these and new species (Phillips & Nelson 1998;
species to be included in many ecological and Zuccarello & West 2003, 2006; Nelson et al
conservation studies, including analyses of the 2006; Zuccarello et al. 2006; Verbruggen et al.
patterns of species richness and endemism 2006). New conservation strategies will have to
(Phillips 2001). It is difficult to study or conserve be developed for the marine biota that has more
species that can not be identified with certainty geographically restricted species than previ¬
(Dayton 2003; Macc 2004). Species are unique ously thought.
entities, conveyed by the species name which is
QUANTITATIVE BIOTIC SURVEYS
not an arbitrary concept, but a summary of the
Biotic sur\^eys are urgently required to address
morphological, ultrastructural, physiological,
the complete lack quantitative data on the
biochemical, ecological, geographical and phylo¬
marine algae/cyanobacterial communities of
genetic characteristics of the entity.
SE Qld. These data are important for environ¬
Our inability to recognise species has mental management and conservation planning.
important implications for environmental and It is expected that these assemblages will be
conservation management, clearly demonstrating spatially variable, occurring in different habitats
that these strategies are as effective as the such as the red algal Bostrydiia/Caloglossa asso¬
reliability of the taxonomy on which they are ciation characteristic of mangroves and also that
based (Knowlton ct nl. 1992; Knowlton & seemingly similar habitats will have differing
Jackson 1994; National Research Council 1995; algal/cyanobacterial assemblages. These assem¬
Wilson 2000; Knowlton 2001; Womersley 2006). blages will also exhibit considerable temporal
Environmental and conservation management variability on seasonal, annual, decadal and
must be underpinned by taxonomic precision longer term time scales in response to environ¬
and accuracy. Identifying constituent species is mental variables. Ecological processes affecting
the key to understanding community structure
algal/cyanobactcrial community structure are
and function, and for detecting the early
complex and long term baseline datasets are
warning signals of environmental change
required to separate natural variability from
before large scale environmental degradation
anthropogenic impacts, and to determine the
and massive species loss become apparent
effects of slow processes (eg global warming),
(National Research Council 1995; Dayton 2003).
episodic phenomena and high annual varia¬
How can we effectively manage or conserve the
bility (Hawkins & Hartnoll 1983; Dayton &
many species we cannot recognise? This is
Tegner 1984; Southward 1991,1995; Barry et al.
particularly pertinent for many widely distri¬
1995; Lewis 1996; Hiscock et al 2003; Thibaut et
buted cosmopolitan or pantropical marine
al. 2005).
'species' now known to be 'species complexes'
comprising two or more, often endemic, super¬ BIOMONITORING
ficially similar sibling or cryptic species Biomonitoring provides accurate appraisals
(National Research Council 1995). Prevalence of ecosystem health by sampling the biota which
of cryptic marine species has ensured that not reflect the summation of all environmental
only has marine biodiversity been variables over spatial and temporal scales rather
underestimated (eg actual invertebrate species than those variables present during sampling
richness is three to five times higher than or being studied (Baldwin & Kramer 1994; Abel
previously recognised for well studied coral reef 1996). Currently, physico-chemical parameters
434 Memoirs of the Queensland Museum — Nature • 2008 • 54(1)
Marine cyanobacterial, algal and plant biodiversity in SE Queensland
are nnonitored in SE Qld estuaries but these, and P loadings into eutrophic estuaries by
even when monitored at frequent intervals, often 30-80% (Jorgensen & Richardson 1996; Boesch
fail to detect the delivery of episodic pulses of et al. 2001; Paerl et al. 2003). Knowledge of the
biologically-significant often peak concentrations biology and ecology of bloom-forming species
of pollutants and nutrients into ecosystems. is also necessary in order to understand why
This is well illustrated by seasonal macroalgal these species cause shifts in species compo¬
blooms which inhabit apparently oligotrophic sition in communities and maintain prolonged
(nutrient-poor) waters (Lapointe & O'Connell competitive dominance (Valiela et al. 1997;
1989; Thybo-Christesen ct al. 1993; Peckol et al. Smayda 1997; Millie et al. 1999).
1994), the result of bloom-forming algae absor¬ Transient algal and cyanobacterial blooms
bing high levels of spatially and temporally which regularly occur in SE Qld coastal waters
variable pulses of water column nutrients within can be expected to become more common with
hours or days (Kiirikki & Blomester 1996; Fong the increasing human population in the region.
et al. 1993a, b; Kamer et al. 2001). Species of the 'green tide' genera Cladophora,
Seagrass depth ranges are currently used for and Ulva (which now includes Enteroworpha)
monitoring water quality in Moreton Bay and phytoplankton (such as Hetcrosigwa akashhoo
(Dennison & Abal 1999), a technique based on (Hada) ex Sournia, Prorocentrum micans Ehren-
declines in many Australian seagrass commu¬ berg, Scrif)psiella trochoidea (Stein) Balech ex
nities attributed to decreased submarine light Loeblich Ill) commonly form blooms in the
penetration from increased water turbidity or region, but it is the cyanobacterial species
epiphyte growth (Bulthuis 1983; Cambridge & Lyngbya niajuscula and Trichodeswium and the
Me Comb 1984; Cambridge et al. 1986; Abal & brown alga Hincksia sordida (Harvey) Silva
Dennison 1996). However, seagrasses occupy which have had the greatest impact in SE Qld.
<5% of the area of Moreton Bay leaving an Periodic, short lived (eg days) blooms of the
urgent need for a more widely applicable bio¬ tropical planktonic Tricliodestmum (often com¬
monitoring system for the bay. monly and erroneously referred to as 'coral
Algal and cyanobacterial species are valuable spawn') are transported into coastal waters in
indicators of ecosystem health (both pristine SE Qld and many localities to Tasmania by the
and degraded ecosystems), responding quickly southward flowing East Australian Current
to anthropogenic-induced changes to the (Ajani et al. 2001).
marine/estuarine environments with changes Recurrent nuisance blooms of Lyngbya
in species composition and abundances in these vmjiiscula have been apparently restricted in
communities. Marked shifts in dominance from Moreton Bay to the eastern banks. Deception
slow-growing perennial macroalgal species of Bay and Puinicestone Passage. The supply of
healthy ecosystems initially to smaller frondose either or both N and P control peak rates of
algae and then finally to fast-growing fila¬ primary production of bloom-forming species
mentous 'nuisance' macroalgal species are early in estuaries (Valiela ct al. 1997). However,
warning signals of increasing nutrient enrich¬ Lyngbya majitscula bypasses N limitation by
ment, triggers to reduce high nutrient loading fixing N2 in the dark (Lundgren et al. 2003;
into aquatic systems long before eutrophication Elmetri & Bell 2004), and not in the light
results in catastrophic algal blooms (Littler & (Dennison et al. 1999) when oxygen-labile nitro-
Murray 1975; Valiela et al. 1997; Omolfsdottir ef genase is degraded during photosynthesis.
al. 2004). The macronutrients N and P have the greatest
ALGAL BLOOMS potential to constrain algal/cyanobacterial
The ongoing and worsening problem of coastal growth (Cloern 2001; Twomey & Thompson
eutrophication has resulted in the increased 2001; Miao et al. 2006). If the micronutrient Fe
frequency and intensity of algal blooms world¬ limits the growth of Lyngbya wajnscula in
wide (Hallegraeff 1993; Chretiennot-Dinet 2001). Moreton Bay (Dennison et al. 1999), P would
Management strategies to ameliorate decadal have to be in excess, contrary to studies which
long macroalgal blooms aim to reduce high N report both the Bay (Eyre & McKee 2002) and
Memoirs of the Queensland Museum — Nature • 2008 • 54(1) 435
Phillips
growth of Moreton Bay Lynghya majusciila and geographical distribution of marine species
(Elmetri & Bell 2004) to be PO4 limited. Clearly, (Hughes 2000). Relatively small changes in
Fe limits cyanobacterial/algal growth in high temperature have already affected marine
nutrient/low chlorophyll remote oceanic regions species (Barry et al. 1995; Southward et al. 1995;
(Coale et al. 1996; Behrenfeld & Kolber 1999), Sagarin et al. 1999), including dramatic declines
where Fe can not be recycled from the ocean in the kelp forests on the Tasmanian east coast
depths and is quickly depleted from surface (Edyvane 2003), but there is little understanding
waters unless replenished by the atmospheric of the effects on the marine biota of larger
transport of terrestrial aeolian dust (Duce & increases in SSTs. We do know that during the
Tindale 1991; Zhaung et al. 1999). In contrast to Quaternary warming episodes, terrestrial plant
these oceanic regions, Moreton Bay has high species responded independently and not as a
chlorophyll levels, the sediments are Fe-rich community moving at different rates and in
(Freda & Cox 2002) and there should be sufficient different directions during climate-induced
bioavailable Fe^*^ from organic material supplied latitudinal shifts in geographical range (Davis
by riverine inputs (Johnson et al. 1999; Wetz et & Bodkin 1985; Overpeck et al. 1991; Jackson &
al. 2006, Tovar-Sanchez et al. 2006). Further¬ Overpeck 2000; Hannah et al. 2005). Conse¬
more, ambient seawater NO3 levels >2.5 |iM quently, novel species associations were created
common in Moreton Bay would inhibit the which may have dramatically altered species
energetically-expensive N fixation in Lyngbya interactions that organised and structured
nmjuscula, similar to the inhibition demon¬ communities.
strated in Trichodesmiiim (Mulholland et al. Changing climate could affect the marine
2001; Holl & Montoya 2005), thus reducing the phototrophs of SE Qld, with many species at or
Fe requirement for nitrogenase and associated near either their southern or northern
metabolic pathways (Howarth ct al. 1988; Paerl distribution limits in this tropical to temperate
1990). This would also be a plausible expla¬ biogeographic overlap zone. Range expansions
nation for the low rates of N2 fixation reported of tropical species and range contractions of
for Moreton Bay Lynghya majusciila by temperate species would potentially alter species
Watkinson ct al. (2005). composition of marine plant/algal communities
During the spring/early summer of 2002 to and, particularly when foundation species are
2005, Hincksia soniida bloomed in the Noosa involved, will impact on marine community
River estuary and at Main Beach, Noosa, greatly structure. Knowledge of the physiology, phen¬
affecting the recreational use of the popular ology and the geographical ranges is urgently
swimming beach (Phillips 2006). During required to predict the response of marine
blooms, bulldozers removed the decomposing phototrophs to climate change. Furthermore,
algal masses fouling the beach, but large extinctions may occur when migrating species
amounts remained suspended in the surf. are deprived of suitable habitat.
Hincksia sordida is an estuarine alga, reported to EXOTIC SPECIES
grow to one metre in length in sheltered Biological invasions threaten the integrity and
Moreton and Port Phillip Bays. The source of function of recipient ecosystems. Human
the massive injections of nutrients into the mediated transport of exotic marine species
Noosa River system and Laguna Bay need to be across their natural dispersal barriers has
identified and reduced in order to prevent probably occurred for centuries (Adams 1983;
future blooms in the area. Ribera & Boudouresque 1995), with only a
EXPECTED EFFECTS OF CLIMATE CHANGE small proportion of introduced species be¬
Average global surface temperature has coming invasive. According to the Tens rule',
increased during the generalised warming trend the probability of an introduced species
of the last 150 years. Sea surface temperature becoming established in the wild and then for
(SST) which is projected to rise by 2-3 °C an established species to become invasive is on
around the Australian continent by 2070 may average 10 % for each transition (Williamson &
potentially affect the physiology, phenology Fitter 1996a, b). Two invasive sea grass species
436 Memoirs of the Queensland Museum — Nature • 2008 • 54(1)