Dispersal rates of seeds and fruits of the 2 common SE Asian seagrasses Enhalus acoroides and Thalassia hemprichii were quantified under field conditions during flotation and the subsequent period of bottom dispersal. For E. acoroides, traveling speeds of buoyant seeds were timed for 70 different experimental batches of 10 to 30 propagules in seagrass beds across 9 different sites on the Bolinao reef flats, and during different seasons and tidal conditions. For T. hemprichii, only 3 experiments could be done due to the limited availability of propagules in this less frequently flowering species. Overall, fruits and seeds of E. acoroides floated at a speed of 0.26 ± 0.02 km h -1 (mean ± standard error), whereas those of T. hemprichii traveled at 0.47 ± 0.15 km h -1 . Median fruit and seed flotation times were 158 and 0.5 h, respectively, for E. acoroides, and 55 and < 0.5 h, respectively, for T. hemprichii. Dispersal rates were similar to in situ measured flows due to tides and wind together. Neither the difference between species nor that between propagule types was significantly different, which is in agreement with their similar sinking velocities in still seawater but in contrast with a marked difference in seed volume and weight. Estimating the distance that could be covered by floating fruits led to medians of 41 and 23 km for E. acoroides and T. hemprichii, respectively, pointing to a considerable dispersal capacity of these propagules. Floating seeds traveled only a limited distance (< 5 km at most for E. acoroides and <13 km for T. hemprichii). In situ bottom dispersal of E. acoroides seeds stopped after 2 to 5 d, i.e. after the germinating seedlings had formed a hairy mass at the base that anchored them to the sediment. Maximum distance traveled over the sediment by observed seeds was 204 cm, and mean rates ranged between 10 and 29 cm d -1 . In 2 of the 3 experiments, seeds of T. hemprichii moved much faster over the sediment (around 100 cm d -1 ) than those of E. acoroides, disappearing from the experimental tracks within 2 to 3 d, probably largely due to herbivory or burial by invertebrates.KEY WORDS: Dispersal · Buoyancy · Reproductive effort · Seagrass · SE Asia · Pollen · Seeds · Fruit Resale or republication not permitted without written consent of the publisher

The effort toward restoring lost mangroves in the Philippines has been commendably immense, specifically during the past two decades. In light of such, it is important to evaluate outcomes and, where appropriate, apply the lessons learned to the current strategies in mangrove forest management. This article synthesizes the results from several research projects assessing the performance of planted mangroves across the country. Overall, there is a widespread tendency to plant mangroves in areas that are not the natural habitat of mangroves, converting mudflats, sandflats, and seagrass meadows into often monospecific Rhizophora mangrove forests. In these nonmangrove areas, the Rhizophora seedlings experienced high mortality. Of the few that survived (often through persistent and redundant replanting), the young Rhizophora individuals planted in these nonmangrove and often low intertidal zones had dismally stunted growth relative to the corresponding growth performance of individuals thriving at the high intertidal position and natural mangrove sites. From this evidence, this article argues that a more rational focus of the restoration effort should be the replanting of mangroves in the brackish-water aquaculture pond environments, the original habitat of mangroves. For such, a number of management options can be explored, the implementation of which will ultimately depend on the political will of local and national governments.

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