1 Coral rehabilitation technique [0001] This application claims priority from Australian Provisional Patent Application No. 2013904729, which is incorporated herein by reference. Technical Field [0002] The invention relates to a method for rehabilitating coral reefs and to a method for promoting coral survival and/or growth. The invention also relates to a coral rearing substrate. Background [0003] Coral reefs represent some of the densest and most varied ecosystems on Earth. They occupy less than 0.1% of the world's ocean surface, yet they provide a home for 25% of all marine species. Coral reefs deliver ecosystem services to tourism, fisheries and shoreline protection. The total net benefit per year of the world's coral reefs is US$29.8 billion. The total value-added economic contribution of tourism, commercial fishing, and cultural and recreational activity to Australia's Great Barrier Reef Catchment Area was estimated at $3.7 billion per year. [0004] Coral reef ecosystems are in danger because they are stressed by pollution, sedimentation, overfishing, introduction of invasive species, vessel groundings, increasing tourism and recreation, and marine debris. Reefs are susceptible to the effects of climate change, such as rising ocean temperatures and ocean acidification. Moreover, reefs are harmed by increasing urbanization, such as agricultural runoff and water pollution. [0005] Research has shown that reefs can be successfully rehabilitated on small scales at desired locations. The current strategies to coral propagation and reef restoration either utilize sexual reproduction of corals or asexual fragmentation of adult corals. The former approach involves taking coral brood stocks out of the reef and spawning them in aquaria on land. Upon larval settlement of corals on tiles or other structures, these materials are then deployed at field sites of interest. The latter approach involves coral aquaculture of broken fragments (nubbins) and transplantation of farmed corals to sites of interest. In both scenarios, the transplantation stage involves manual labour to secure the corals/tiles by plastic pegs or masonry anchors or with epoxy glue to the substratum in the field. 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 2 [0006] Importantly, very low survival rates of juvenile corals are common to both restoration schemes. To enhance the success of active reef restoration further mitigation strategies are required to improve health and survival of outplanted corals. [0007] Hence, any technology that lowers the frequency and effort of coral maintenance in the field by human intervention has the potential to improve the economic feasibility of active reef restoration. Summary [0008] In a first aspect, the invention provides a method for rehabilitating a coral reef, comprising: locating or inducing coral to locate on a surface of a coral rearing substrate, wherein the surface of the coral rearing substrate is coated with an antifouling coating. [0009] In a second aspect, the invention provides a method for promoting coral survival and/or growth on a coral rearing substrate, comprising: locating or inducing coral to locate on a surface of the coral rearing substrate, wherein the surface of the coral rearing substrate is coated with an antifouling coating. [0010] Prior to the present invention, coral rehabilitation techniques have involved cleaning cultivated coral. This maintenance regime represented a significant cost of active reef restoration as this procedure is manually performed by divers. The antifouling coating reduces the need for this cleaning by preventing fouling of the maturing coral, providing a method for improving survival of outplanted coral. [0011] In a third aspect, the invention provides a method for preparing a coral rearing substrate, comprising applying an antifouling coating to a surface of the coral rearing substrate. [0012] In a fourth aspect, the invention provides a coral rearing substrate comprising a surface coated with an antifouling coating for promoting coral survival. [0013] The coral rearing substrate of the fourth aspect may be used in the method of the first and second aspects. 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 3 Brief Description of Drawings [0014] The invention will be further described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a graph showing fouling cover (percent) on three substratum types (control, N-Wax, S-Wax) in four replicate water tables (tanks A-D). Figure 2 is a graph showing cumulative survival of A. millepora spat on three substratum types (control, N-Wax, S-Wax) over 39 days. Figure 3 is a graph showing a linear regression analysis of percentage survival and fouling cover per replicate (Linear regression statistics are shown in Table 1). Figure 4 is a graph showing a linear regression analysis of percentage survival and fouling cover per replicate for N-Wax (square), S-Wax (triangle) and control (diamond) with linear fits for N-Wax and the control (Linear regression statistics are shown in Table 1). Figure 5 is a graph showing required cleaning time for the coral rearing substrates (N-Wax, P Wax and control) in seconds per replicate block. Description of Embodiment(s) [0015] The invention provides a method for rehabilitating a coral reef and/or promoting coral survival and, preferably, coral growth. The method comprises locating or inducing coral to locate on a surface of a coral rearing substrate. The surface of the coral rearing substrate is coated with an antifouling coating. [0016] Ecological studies of early post-settlement mortality of corals are difficult because corals less than one year of age (defined as coral recruits) are usually too small (i.e. < 1 cm diameter) to be identified in situ. As a result most field studies of early population dynamics omit newly recruited corals, focusing instead on juvenile corals that can be seen with the naked eye, typically > 1 cm diameter. Corals of this size are likely to be at least one year old, and consequently our understanding of the factors that influence the mortality bottleneck in the first year of a coral's life remains limited. [0017] Studies of early coral mortality have for the most part relied on monitoring the survival of recently settled corals in situ or ex situ on artificial substrata. Experiments with laboratory-reared coral spat transplanted to the reef have shown that survival of newly settled corals (days to a few weeks after settlement) is typically < 15% in the first three to four months. However, direct evidence for the causes of high coral spat mortality is limited and often constrained by insufficiently frequent sampling. Known causes of mortality of coral spat include 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 4 smothering, sedimentation, chemical warfare, pathogens, settlement on unsuitable substrates, and accidental removal by grazing fish or direct predation. [0018] Fouling is the accumulation of micro- (bacteria, fungi, protozoa, etc.) and macroorganisms (algae and animals) on immersed hard substrata. The interaction between corals and fouling organisms, particularly algae, is generally deemed to be detrimental for the health of adult corals and settlement of coral larvae. The extent and type of benthic fouling is also likely to affect variation in mortality during the early life stages of corals. Fouling can impact coral spat in at least two ways: through competition from adjacent fouling organisms on the substratum or by direct fouling of the spat themselves by microorganisms or motile propagules of other macroorganisms. Furthermore, the microtopography provided by fouling may also enhance passive deposition of inanimate material such as sediment onto coral recruits or provide a refuge for microbial pathogens. For example, in a common Hawaiian coral, mortality of planulae and settled spat increased in the presence of macroalgae and possibly resulted from increased microbial activity. [0019] One of the main mortality factors identified for juvenile coral (including both coral spat and coral nubbins) is overgrowth by filamentous macroalgae. Prior to the present invention, it has been common practise to clean coral nubbins of fouling algae on a regular basis. This maintenance regime is a significant cost driver of active reef restoration as this procedure can only be manually performed by divers. The present invention reduces the need for this cleaning by providing a method for improving survival of outplanted coral. In one embodiment, the method described herein requires less regular cleaning or requires less time spent on average cleaning the coral on each maintenance dive. In more preferred embodiments, the coral does not require any substantial cleaning. In such embodiments, the coral may be uncleaned coral. The typical time period required to clean a coral nursery containing 1000 corals using prior art techniques is 96 person hours and 6 boat days (this roughly equates to about 10 person hours for each 100 corals), and the frequency of cleaning dives was one half day per month. Thus, according to some embodiments, the time period for cleaning coral is not more than 85 person hours per nursery having about 1000 corals. Even shorter time periods can be achieved, such as not more than 75 hours, not more than 65 hours, or not more than 50 hours per nursery having about 1000 corals. Also, according to some embodiments, the time period for cleaning coral is not more than 7.5 person hours per 100 corals. Even shorter time periods can be achieved, such as not more than 7 hours, not more than 6 hours, or not more than 5 hours per 100 corals. According to some embodiments, the 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 5 frequency between cleaning dives is one half day every 6 weeks, preferably 2 months, preferably 3 months, or greater. [0020] The inventors' experimental data demonstrate that surrounding coral spat with an antifouling perimeter leads to significantly increased survival of coral spat. In one trial, surrounding coral nubbins on concrete pedestals with an antifouling coating resulted in greater than a two-fold reduction of cleaning time per nubbin, equating to >50% cost reduction of underwater man hours. At one study site (US Virgin Islands), this reduction represented a savings of >$25,000 p.a. The methods described herein are believed to be globally applicable for the restoration of corals, i.e. may be used in a variety of aquatic environments and may promote the growth of various types of corals. [0021] The method is applicable for both sexual reproduction of corals or asexual fragmentation of adult corals. The method may also be used in conjunction with existing coral reef rehabilitation techniques. For examples of such techniques see William F. Precht (ed), Coral Reef Restoration Handbook., CRC Press 2006, and Edwards, A. J. (ed.) (2010) Reef Rehabilitation Manual, Coral Reef Targeted Research & Capacity Building for Management Program: St Lucia. Australia. ii-166pp, which are incorporated herein by reference. [0022] In one embodiment, the method described herein comprises forming a coral nursery in a body of water, wherein the coral nursery comprises one or more of the coral rearing substrates. [0023] The body of water may be any body of water within which coral may be located or induced to locate on a coral rearing substrate and mature into settled coral. Suitable bodies of water include, for example, the ocean or other saltwater body of water. [0024] The number of coral rearing substrates required will depend on the size of the rehabilitation site and the available suitable space in the body of water. For example, the coral nursery may comprise 1, 2, 3, 4, 5, 10, 20, 50, 100, 150, 200, 250, 300, 400, 500 or more coral rearing substrates. [0025] The coral may be recruited to the surface coated with the antifouling coating within the coral nursery. In one embodiment, the method described herein comprises locating or inducing coral to locate on the surface of the coral rearing substrate within the coral nursery. 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 6 The recruitment of coral to the surface of the coral rearing substrate may involve locating a coral fragment of opportunity, for example, a coral nubbin, on the surface of the coral rearing substrate and optionally fixing the fragment to the surface of the coral rearing substrate. Alternatively, the recruitment may involve locating a coral settlement recruiter, such as crustose coralline algae (CCA), organic solvent extracts of these algae, a microbiofilm or constituents of a microbiofilm, on the surface of the coral rearing substrate to induce coral, for example, coral larvae, to locate on the surface of the coral rearing substrate. Alternatively, the coral may be located or induced to locate in a laboratory setting, for example, within a tank. [0026] Once the coral has matured sufficiently and coral settlement has been induced, the settled coral may be transferred from the coral rearing substrate to the rehabilitation site. Consequently, in one embodiment, the method comprises transferring the settled coral from the coral growth substrate to the coral reef. As matured coral is more robust, it is preferred to delay transfer until settlement has been induced. Therefore, preferably, the coral is incubated on the coral rearing substrate for a first period of time until the coral has matured into settled coral. Preferably, the first period of time is at least about 2 weeks or more. In one embodiment, the first period of time is about 2 weeks to about 14 months. In another embodiment, the first period of time is about 6 months to about 12 months. [0027] In one embodiment, the method described herein may further comprise incorporating the coral rearing substrate into the coral reef. In this embodiment, the method may involve cultivating coral in a coral nursery and transferring the coral rearing substrate together with settled coral on the surface of the coral rearing substrate to a coral reef requiring rehabilitation. Alternatively, the coral rearing substrate may be installed directly at the reef rehabilitation site and coral may be located or induced to locate on the surface of the coral rearing substrate at the rehabilitation site. The installation of a coral growth substrate may involve placing a prefabricated coral rearing substrate in the rehabilitation site, or may involve constructing or fabricating the coral rearing substrate in situ. [0028] In one embodiment, the method further comprises applying the antifouling coating to the surface of the coral rearing substrate. Any suitable means of applying an antifouling coating known in the art may be used. For example, the antifouling coating may be applied by any one of dip coating, spray coating or brush coating. [0029] The antifouling coating should subsist for sufficient time to allow the coral located on the coated surface to mature. It will be appreciated that coating adhesion will depend, in part, 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 7 on the properties of the surface of the coral rearing substrate. Consequently, in one embodiment, the method comprises modifying the surface of the coral rearing substrate with an adhesive to promote adhesion of the antifouling coating. Any suitable adhesive may be used to promote adhesion of the antifouling coating to the surface of the coral rearing substrate. Suitably, the adhesive may be a resin, for example, an epoxy resin. [0030] The coral located or induced to be located on the surface of the coral rearing substrate may be a juvenile coral, such as a coral nubbin, or a coral recruit, such as a coral larvae. In one embodiment, a coral recruit is induced to locate on the surface of the coral rearing substrate by providing a coral settlement recruiter on the surface, such as, for example, crustose coralline algae. In another embodiment, a juvenile coral is located on the surface, and optionally fixed to the surface with an adhesive, such as, for example, an epoxy resin. [0031] In one embodiment, the method comprises modifying the surface of the coral rearing substrate with epoxy resin, and then dipping the coral rearing substrate into an antifouling coating composition, to coat the entire surface of the coral rearing substrate with an antifouling coating. The antifouling coating composition may comprise molten paraffin wax. Coral rearing substrate [0032] The invention also provides a coral rearing substrate comprising a surface coated with an antifouling coating for promoting coral survival. [0033] The antifouling coating on the surface of the coral rearing substrate extends sufficiently across the surface of the coral rearing substrate to provide an antifouling perimeter surrounding the location for the coral. The coral may be located or induced to be located on the surface of the coral rearing substrate at a position which is not coated, provided that the position is surrounded by antifouling coating. In one embodiment, the antifouling coating coats the entire surface of the coral rearing substrate. In another embodiment, the antifouling coating coats the entire coral rearing substrate. [0034] The coral rearing substrate is any suitable article or object comprising a surface that may be coated with an antifouling coating and that may support coral settlement. For example, the article or object may be selected from a tile, a brick, and concrete; i.e. the coral rearing substrate may be selected from a tile, a brick or concrete. 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 8 [0035] In one embodiment, the surface of the coral rearing substrate comprises one or more bores. Coral may be located or induced to locate within the one or more bores. The bore may provide additional shelter to the juvenile coral from water currents and turbulence and aids in retention of the coral within the antifouling perimeter established by the antifouling coating. In one embodiment, the antifouling coating extends across a region of the surface of the coral rearing substrate. The antifouling coating may be applied prior to or after creating the bore in the surface, provided that a sufficient area surrounding the bore is coated to promote coral settlement. [0036] The antifouling coating should subsist on the surface of the coral rearing substrate for a sufficient period of time to allow the coral to mature. In order to ensure that the coating subsists when immersed in saltwater, an adequate thickness of antifouling coating may be applied. For example, the antifouling coating is preferably at least about 1 mm thick, more preferably about 1 mm to about 2 mm thick. The person skilled in the art will be able to determine an adequate thickness for a selected antifouling coating. [0037] The antifouling coating may be any coating that is non-toxic to coral growth and otherwise antifouling. The antifouling coating preferably comprises, or consists essentially of a paraffin wax. [0038] Non-toxic antifouling paints based on paraffin wax have been described in different contexts. For example, Australian Patent No. 2007276712 describes a bi-phasic biodegradable polymer mixture; Australian Patent Application No. 2003262507 describes a formulation used as a physical barrier for molluscs; and US Patent No. 4,098,925 describes a physical barrier for ships hulls, these documents are incorporated herein by reference. Waxes are generally environmentally benign and wax coating to reduce fouling and epibiotic coverage on immersed artificial structures has been reportedly employed since about 300 BC. [0039] For example, the antifouling coating may comprise an antifouling resin manufactured by Ecozean Pty Ltd (EZ001-2) or alternatively, pure paraffin (TrendLight, 55 0 C melting point). [0040] In some embodiments, the antifouling coating further comprises an additive. 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 9 [0041] The additive may be selected from any one of an adhesion promoter, a coral growth promoter, an antifouling enhancer and a combination thereof. [0042] An adhesion promoter is any agent that increases the adhesion of the antifouling coating to the surface of the coral rearing substrate. Suitable adhesion promoters include epoxy resin, and the like. [0043] A coral growth promoter is any additive which further promotes coral growth. For example, for trials conducted with an antifouling coating comprising silicone oil, a non-linear increase in coral survival was observed. [0044] Depending on the coral rearing substrate selected, the antifouling coating may require modification of the surface of the coral rearing substrate to be modified to enhance adhesion of the coating to the surface. In one embodiment, the antifouling coating is adhered to the surface with an adhesive. The adhesive may be a resin, preferably an epoxy resin. [0045] Another type of additive that may be used is an antifouling enhancer. An antifouling enhancer is a substance that is capable of enhancing the antifouling effect of the antifouling coating. Since this effect can lead to further coral growth, in practice, such additives function as both antifouling enhancers and as coral growth promoters. Examples of suitable antifouling enhancers include silicone oils. As mentioned above, for trials conducted with an antifouling coating comprising silicone oil, a non-linear increase in coral survival was observed. This increase may be due to the enhanced antifouling effects of the antifouling enhancer additive. Some paraffin-based antifouling coatings comprise a crystalline phase and an amorphous phase. Without wishing to be bound by theory, the inventors believe that the addition of silicon oil may promote the degradation or disrupt the amorphous phase of the paraffin, revealing a greater amount of the crystalline phase and resulting in a surface morphology less conducive to fouling. This process has been likened to revealing a "bed-of-nails". [0046] The additive may be present in the antifouling coating in an amount of about 0.001 wt% to about 30 wt%, preferably about 0.001 wt% to about 10 wt%, more preferably about 0.01 to about 1 wt%. [0047] Also described herein is a method for rehabilitating a coral reef, or for promoting coral survival and, preferably, growth, comprising locating or inducing coral to locate on the coral rearing substrate of the invention. 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 10 [0048] Also described herein is the use of the coral rearing substrate of the invention in a method of the invention. [0049] The invention also provides a method for preparing a coral rearing substrate for promoting coral survival, comprising applying an antifouling coating to a surface of the coral rearing substrate. [0050] Any method of coating the surface of the coral rearing substrate with antifouling coating known in the art may be employed. In one embodiment, the antifouling coating is applied by any one of spray coating, dip coating or brush coating. [0051] As described above, the surface of the coral rearing substrate may be modified with an adhesive to promote adhesion of the antifouling coating such that the coating will sufficiently subsist on the surface of the coral rearing substrate to allow coral maturation when the coral rearing substrate is immersed in a body of water or a tank. [0052] As described above, the coral rearing substrate may also be physically modified. For example, one or more bores may be drilled into the surface of the coral rearing substrate. Further, the coral rearing substrate may be permanently fixed within a coral nursery or at a rehabilitation site. [0053] The invention will be further described in the following non-limiting Examples. It will be understood to persons skilled in the art of the invention that many modifications may be made without departing from the spirit and scope of the invention. Examples [0054] The following examples refer to two separate experiments that tested the effect of different wax-based antifouling coatings on: A: fouling cover and survival of coral spat in a tank experiment B: fouling cover and cleaning time of coral nubbins in a field experiment A. Fouling cover and survival of coral spat (tank experiment) [0055] Uncoated (control) and wax-coated (treatment) terracotta tiles (20 x 20 cm, n = 16) were prepared for a 39-day survival study of coral spat in a flow through water tables. Tiles 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 11 were primed with a thin film of resin (EZ100050P, Ecozean Pty Ltd, Sydney, Australia) to increase wax adhesion and dip-coated with wax (EZ001-2, Ecozean Pty Ltd, Sydney Australia), hereafter referred to as N-Wax. The same wax was used in a second treatment containing 0.1 % silicone oil (hereafter referred to as S-Wax). [0056] Forty-nine wells (5 mm wide and 2 mm deep, 7 x 7 arrays) were drilled into each tile and filled with 1 pl of powdered crustose coralline algae (CCA) in sterile filtered seawater (FSW) to render the wells inductive to larval settlement. Batches of tiles (n = 5 per treatment) containing wells filled with CCA were placed into 4 water tables containing competent coral larvae (from 6 d post spawning, density < 0.5 larvae ml 1 , 500 I tank volume) for no longer than 24 h. Tiles containing coral spat were maintained in FSW until the start of the experiment to ensure that all spat were exposed to the same fouling pressure. This procedure resulted in 48 tiles (16 per tank treatment) containing at least 10 wells with coral spat. The total number of coral spat on tile surfaces outside the designated wells was less than 10%. These spat were ignored in the survival study. Tiles were fully immersed in four shallow constant flow-through (sand filtered) tray tanks (2 m x 0. 7 m x 0.1 m length x width x water depth). Fouling [0057] The mean percentage of fouling cover on experimental tile surfaces was measured after 39 days in 5 x 5 mm quadrats positioned directly over three randomly selected microwells per replicate tile. Fouling was estimated via photographs of each quadrat and analysed using the Coral Point Count Software with Excel extensions (CPCe) (Kohler & Gill 2006). Thirty-two points per 25 mm 2 quadrat were analysed by stratified random point counts in 4x4 columns and rows and 2 points per cell. The surfaces categorized into fouled (e.g. macroalgae, microalgae, sediment) and non-fouled (non-fouled coral spat and tile surface with no visible fouling) groups. [0058] After 39 days, the percentage cover of fouling was significantly higher on control tiles (84.9 ± 3.6 %, mean ±SE) compared to N-Wax (41.3 % ± 3.2 %, mean ± SE, Tukey HSD, P < 0.01) and S-Wax tiles (35.2 2.5 %, mean ± SE, Tukey HSD, P < 0.01), with no significant difference between the two wax types (Fig 1). There was no effect of tank location on fouling (two-way AVOVA, F3,36 = 2, P = 0.12) and no interaction between tank location and tile type (two-way AVOVA, F6,36 = 71.3, P = 0.80). 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 12 Survival [0059] Kaplan-Meier survival analysis (Fig. 2) revealed that mean survival time of coral spat on untreated terracotta tiles (27.9 ± 0.6 days (mean ± SE)) was significantly shorter (log rank test, P < 0.001) than on surfaces coated with either one of the antifouling resins (31.8 ± 0.5 d, N-Wax; 36.8 ± 0.2 d S-Wax) (Fig. 2). There was no significant difference in survival times between the wax treatments. At the end of the experiment and across all treatments, the majority of live coral spat acquired zooxanthellae and developed daughter polyps, suggesting normal development. After 39 d, the proportion of wells containing at least one live coral spat was 40.4 ± 9.1% (mean ± SE, n = 460) for untreated terracotta tiles, 67.2 ± 5.6% (mean SE, n = 529) for N-Wax tiles and 72.3 4.1% (mean ± SE, n = 439) for S-Wax tiles. There was a significant effect of tile type (two-way ANOVA, F2,6 = 7.96, P = 0.021), no significant interaction between tile type and tank location (F6,36 = 0.78, P = 0.59) and no significant effect of tank location (F3,36 = 0.45, P = 0.72) on percentage survival. Survival on N-Wax (Tukey HSD, P = 0.025) and S-Wax (P = 0.007) was significantly greater than on control tiles, but did not differ between each antifouling treatment (P < 0.05). Correlation of spat survival and fouling [0060] Linear regression analysis of spat survivorship and percentage fouling cover on all tile treatments (Fig. 3, Table 1) revealed a significant negative effect of fouling on survival (N = 48; F = 27.06; P < 0.001, R2 = 0.37). Separate regression analyses for different treatments (Fig. 4) resulted in a significant negative correlation of spat survival and fouling cover for the control (N = 16; F = 11.24; P < 0.005; R2 = 0.45) and the N-Wax treatment (N = 16; F = 6.97; P < 0.02; R2 = 0.33), and no significant correlation for the S-wax treatment (N = 16; F = 0.98; P = 0.34). Table 1: Linear regression analyses of spat survival and. fouling cover on different tile surface treatments. NS=not significant. N F Significance R2 Pooled 47 27.06 < 0.001 0.37 Control 15 11.24 < 0.005 0.45 N-Wax 15 6.97 0.02 0.33 S-Wax 15 0.98 0.34 (NS) B. Fouling cover and cleaning time of coral nubbins (field experiment) [0061] Coral rearing substrates (cinder blocks; 20 x 20 x 40 cm height x depth x length), PVC pipes (10 x 5 cm diameter) and concrete pedestals (2 cm high, 5 cm diameter) were primed with resin (EZ100050P, Ecozean Pty Ltd, Sydney, Australia) to increase wax adhesion 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 13 and dip-coated with N-Wax (EZ001-2, Ecozean Pty Ltd, Sydney Australia). In a second treatment, paraffin wax (hereafter referred to as P-Wax) was dip-coated directly onto the coral rearing substrates. [0062] Fragments of opportunity of Acropora palmata were collected from an adjacent reef (St. Croix, USVI), transported to the inshore nursery to acclimatize and were further fragmented to 10 fragments (1 cm each). Only healthy coral fragments were used (healthy living tissue on both sides of the cut). These coral 'nubbins' were attached to the cement pedestals with AlIFix Expoxy glue and set up in an inshore reef at the US Virgin Islands. This nursery site is characterized by low hydrodynamic flow and is thus exposed to intensive fouling pressure by filamentous macroalgae. [0063] To assess the fouling cover, monthly photographs of the front and back of the blocks were taken for all treatments and controls from an equal distance (1.5 m). A colour card and identification number was held into frame. One set of blocks (n=5) was cleaned monthly with gloved hands for the wax treated surfaces and with a wire brush (1 inch) for the non treated surfaces. This set was used to determine the difference between cleaning effort/time of the standard method (control) and treatments that decreased fouling adhesion. Another set of blocks remained uncleaned to determine the development of fouling on the coral rearing substrates without any cleaning. Fouling [0064] The coverage of fouling increased over time on all treatments. At the observation time point July 2013 the percentage fouling cover on different surface treatments was the same (one way ANOVA, p = 0.55). Cleaning time [0065] At each observation time point, the required cleaning time on N- and P-wax coated surfaces was significantly shorter than on control surfaces (Table 2, Figure 5). On average, cleaning time at the study site where we worked (US Virgin Islands) is reduced by > 50% for each pedestal the nubbins are placed on. The nursery is stocked with 200 pedestals. Without antifouling technology, these substrates require a biweekly cleaning regime involving 6 days of work by 2 divers (daily remuneration 300 $ per diver). Including boat fuel, tank fillings and remuneration of divers the annual expenditure to control fouling in the nursery is US$52,000. 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 14 The application of the antifouling technology described herein results in annual savings of > US$25,000 at this one site and is globally applicable for coral restoration. Table 2. Statistical comparison (one-way ANOVA) of required cleaning time for coral rearing substrates coated with N- and P-wax, and on an untreated control. Date N-Wax P-Wax Control One-way ANOVA 09/04/13 110.2 ±8.1 116.6± 13.3 326.2 ±25.9 P<0.01 08/05/13 100.8 ±7.6 130.6± 11.6 275.8 ±26.8 P<0.01 10/06/13 153.6 ± 14.4 168.0 ± 16.8 397.4 ± 16.3 P<0.01 08/07/13 194.0 ± 26.8 205.6 ± 8.0 423.6 ± 27.0 P<0.01 08/08/13 140.0 ±18.3 141.6 ±15.8 422.2 ±21.1 P<0.01 09/09/13 109.0 ±20.6 136.4 ±19.4 322.8 ±11.1 P<0.01 [0066] It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country. [0067] In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 15 [0068] Preferred aspects and embodiments described herein include the following items 1 to 36. 1. A method for rehabilitating a coral reef, comprising: locating or inducing coral to locate on a surface of a coral rearing substrate, wherein the surface of the coral rearing substrate is coated with an antifouling coating. 2. The method of item 1, comprising forming a coral nursery in a body of water, wherein the coral nursery comprises one or more of the coral rearing substrates. 3. The method of item 2, comprising locating or inducing coral to locate on the surface of the coral rearing substrate within the coral nursery. 4. The method of any one of items 1 to 3, comprising incubating the coral for a first period of time until the coral has matured into settled coral. 5. The method of item 4, comprising transferring the settled coral from the coral rearing substrate to the coral reef. 6. The method of any one of items 1 to 4, comprising incorporating the coral rearing substrate into the coral reef. 7. A method for promoting coral survival on a coral rearing substrate, comprising: locating or inducing coral to locate on a surface of the coral rearing substrate, wherein the surface of the coral rearing substrate is coated with an antifouling coating. 8. The method of any one of items 1 to 7, further comprising applying the antifouling coating to the surface of the coral rearing substrate. 9. The method of item 8, wherein the antifouling coating is applied by any one of dip coating, spray coating or brush coating. 10. The method of any one of items 1 to 9, wherein the antifouling coating coats the entire surface of the coral rearing substrate. 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 16 11. The method of any one of items 1 to 10, wherein the antifouling coating comprises a paraffin wax. 12. The method of any one of items 1 to 10, wherein the coating consists essentially of a paraffin wax. 13. The method of any one of items 1 to 11, wherein the coating further comprises an additive. 14. The method of item 13, wherein the additive is selected from any one of an adhesion promoter, a coral growth promoter, an antifouling enhancer and a combination thereof. 15. The method of any one of items 1 to 14, comprising modifying the surface with an adhesive to promote adhesion of the antifouling coating. 16. The method of item 15, wherein the adhesive is a resin. 17. The method of item 15 or item 16, wherein the adhesive is an epoxy resin. 18. The method of any one of items 1 to 17, wherein the coral is a juvenile coral or a coral recruit. 19. The method of any one of items 1 to 18, wherein the method comprises inducing coral to locate on the surface of the coral rearing substrate. 20. The method of item 19, comprising inducing coral to locate on the surface by providing a coral settlement recruiter on the surface. 21. The method of item 20, wherein the coral settlement recruiter is crustose coralline algae. 22. A method for preparing a coral rearing substrate for promoting coral growth, comprising applying an antifouling coating to a surface of the coral rearing substrate. 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 17 23. A coral rearing substrate, comprising a surface coated with an antifouling coating for promoting coral growth. 24. The coral rearing substrate of item 23, wherein the antifouling coating coats the entire surface of the coral rearing substrate. 25. The coral rearing substrate of item 23 or item 24, wherein the surface comprises a bore. 26. The coral rearing substrate of any one of item 23 to 25, wherein the coating is at least about 1 mm thick. 27. The coral rearing substrate of any one of items 23 to 26, wherein the coral rearing substrate is selected from concrete, a tile and a brick, and the surface is a surface of said concrete, tile or brick. 28. The coral rearing substrate of any one of items 23 to 27, wherein the antifouling coating comprises a paraffin wax. 29. The coral rearing substrate of any one of items 23 to 27, wherein the coating consists essentially of a paraffin wax. 30. The coral rearing substrate of any one of items 23 to 28, wherein the coating further comprises an additive. 31. The coral rearing substrate of item 30, wherein the additive is selected from any one of an adhesion promoter, a coral growth promoter, an antifouling enhancer and a combination thereof. 32. The coral rearing substrate of any one of items 23 to 31, wherein the antifouling coating is adhered to the surface with an adhesive. 33. The coral rearing substrate of item 32, wherein the adhesive is a resin. 60121741 (GHMatters) P95447.AU DANNYG 3/12/14 18 34. The coral rearing substrate of item 32 or item 33, wherein the adhesive is an epoxy resin. 35. A method for rehabilitating a coral reef, or for promoting coral growth, comprising locating or inducing coral to locate on the coral rearing substrate of any one of items 23 to 34. 36. Use of the coral rearing substrate of any one of items 23 to 34 in the method of any one of items 1 to 21. 60121741 (GHMatters) P95447.AU DANNYG 3/12/14