娘子关泉域藻类植物的初步研究

1984～2000年间,对娘子关泉域的藻类植物进行了15次采集,共采得藻类植物标本200余号。经鉴定,有107种,隶属7门,32科,49属。其中,以绿藻门的种类最多,有13科,19属,45种。其次是裸藻门,有2科,7属,26种。排在最后的是轮藻门,有1科,1属,3种。群落主要包括8类,即刚毛藻-红毛菜群落(Cladophora Bangia community),刚毛藻群落(Cladophora community),拖拉藻-轮藻群落(Chara Thorea community),弯枝藻-拖拉藻群落(Composopogon-Thorea community),水绵-双星藻群落(Spirogyra Zygnema community),无隔藻群落(Vaucheria community),串珠藻群落(Batrachospermum community)和泡状饶氏藻群落(Jaoa community)。其中,有的群落类型已趋于消失或消失,许多种类已成为濒危物种,其原因主要是人为因素造成藻类植物生存环境的改变或破坏。本文也提出了相应的保护对策。     

Settlement behavior of cyphonautes larvae of the bryozoan Membranipora membranacea in response to two algal substrata

Abstract. Settlement is an important process in the biphasic life histories of many marine invertebrates. Little is known regarding the fine-scale behavioral mechanisms for finding and attaching to a suitable substratum, particularly under conditions that may impose a potential challenge, such as flow. In this study, we examined the settlement behavior of cyphonautes larvae of the bryozoan, Membranipora membranacea, in response to two different algal substrata. Larvae showed a strong preference for settling on the kelp Nereocystis luetkeana over the red alga Mazzaella splendens. We then tested whether the behavioral mechanisms used by larvae to attach to these algae differed when presented with the challenge of flowing water during settlement. We found that larvae exhibited different behaviors on the two species of algae in flowing water. Larvae were more often observed in direct contact with the preferred alga (N. luetkeana) exhibiting fine-scale active search behaviors. On the less preferred alga (M. splendens), larvae were less frequently observed in direct contact with the alga, and appeared to be exhibiting broad-scale passive search behaviors along the surface of the blade. Our results suggest that cyphonautes larvae alter their behavior in response to their preferred settlement habitat.     

BENTHIC ALGAL COMMUNITIES OF THE METOLIUS RIVER1,2

Sampling of benthic algae from selected sites in the Metolius River was carried out at regular intervals between April 15, 1967 and March 9, 1968 to determine the species composition of the communities. With the exception of the sampling site at the headwaters and the site immediately downstream, the benthic community of the Metolius River is described as a Cladophora–Achnanthes–Spirogyra community, with species of these 3 genera predominating on a year-round basis. The community described for the headwaters and the sampling site immediately downstream was composed primarily of Nitzchia palea and Cymbella cistula. Of the approximately 60 species of algae which were identified, only 9 showed a definite seasonal distribution, the remaining species being found on a year-round basis.     

Amphipods exclude filamentous algae from the Western Antarctic Peninsula benthos: experimental evidence

Hard bottom, subtidal communities along the Western Antarctic Peninsula are dominated by forests of large, chemically defended macroalgae that support a very dense assemblage of amphipods. Free-living filamentous algae are rare in the subtidal, but filamentous algal endophytes are common in many of the larger macroalgae, both likely as the result of amphipod grazing pressure. Filamentous algae are common in the intertidal, but primarily in the upper intertidal and on high-energy shores where amphipods are likely to be excluded much of the time. We tested the hypothesis that free-living, filamentous algae would be rapidly consumed if transplanted from the intertidal to the subtidal, and our results clearly supported this hypothesis. The filamentous, intertidal green alga Cladophora repens was transplanted to the benthos in 6 different macroalgal habitats. Control algae were transplanted in 3 m deeper waters nearby (usually 12 m or less laterally) but suspended 3 m off the bottom where amphipods are absent or rare. Overall consumption during approximately 6 h on the bottom ranged from 22 to 98% of the initial biomass, while significantly less biomass loss occurred in the water column.     

Cadmium removal using Cladophora in batch, semi-batch and flow reactors.

This study presents the results of using viable algae to remove cadmium from a synthetic wastewater. In batch and semi-batch tests, a local strain of Cladophora algae removed 80-94% of the cadmium introduced. The flow experiments that followed were conducted using non-local Cladophora parriaudii. Results showed that the alga removed only 12.7(+/-6.4)% of the cadmium introduced into the reactor. Limited removal was the result of insufficient algal quantities and poor contact between the algae and cadmium solution.     

绿球藻目的几个中国新记录属种

6个生境比较特殊而有趣的绿球藻目物种首次在我国发现,它们分别是生于土壤的香喇网绿藻(Dictyochloris fragrans Vischer ex Start),寄生于眼子菜叶片的浮萍绿点藻(Chlorchytrium lemmae Cohn.),气生种类—生长在樟树皮上的分层胶囊藻(Gloeocystis polydermatica(Kutz.) Hindak),与真菌共生形成地衣的土著共球藻(Trebouxia aboricola de Puymaly)和团集共球藻(Trebouscia glomerata(Waren) Ahmadjian),还有附生于一种刚毛藻(Cladophora sp.)细胞表面的伊乐外生藻(Ectogeron elodeae Dangeard)。除胶囊藻属(Gloeocystis)外,其它属均为中国新记录属。     

Über tagesperiodische Änderungen der sichtbaren Fläche von Nucleus und Nucleolus einheimischer Süßwasseralgen und ihre Beeinflußbarkeit

Zusammenfassung In unseren Versuchen an Zellkernen und Kernkörperchen vonSpirogyra crassa konnten tagesperiodische Schwankungen der Projektionsfläche (als Ausdruck des Volumens) aufgefunden werden. Sowohl die Zellkerne als auch die Kernkörperchen dieser Alge waren um 12 Uhr mittags am größten und um Mitternacht am kleinsten, wobei die Größenschwankungen des Nucleus größer waren als die des Nucleolus.Eine halbstündige Erhitzung derSpirogyra crassa- Zellen hatte eine Vergrößerung der Projektionsfläche der Zellkerne und Kernkörperchen zur Folge, eine gleich lange Abkühlung eine Verkleinerung. Die anschließend an die Hitze- bzw. Kältebehandlung alle vier Stunden gemessenen Flächenschwankungen entsprachen jenen der unbehandelten Kerne und Kernkörperchen. Kurz vor Eintritt des Zelltodes zeigten jedoch die durch Kälteeinwirkung zum Absterben gebrachten Nuclei und Nucleoli eine Vergrößerung der sichtbaren Fläche, die als Folge der Erhitzung absterbenden eine Verkleinerung.Eine dreitägige Kurzbehandlung der AlgenCladophora fracta undZygnema sp. hatte eine Verkleinerung der Zellkerne gleichlaufend mit einer Abnahme der Hitzeresistenz zur Folge, in einer anschließenden Nachkultur bei normaler Tageslichtlänge erwarben die Algen wieder ihre ursprüngliche Größe der Kernfläche und ihre anfängliche Hitzeresistenz.Es ist zu erwarten, daß ähnliche Kerngrößenänderungen auch am natürlichen Standort im Tages- und Jahresgang in Abhängigkeit von Temperatur und Tageslichtlänge auftreten.

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Diurnal variation in surface area of the nucleus and nucleolus of common freshwater algae and the possibility of experimental alteration

Summary The freshwater algaSpirogyra crassa was found to have a marked diurnal change in size of the nucleus and nucleolus. The nuclei were largest at noon (median size 231.85 ²) and smallest at midnight (median size 142.07 ²). The change in size of the nucleoli was smaller than that of the nuclei, it varied between 39.42 ² (median size at noon) and 35.24 ² (median size at midnight).In further experiments cells ofSpirogyra crassa were cooled to –4° C and heated to + 42° C for half an hour. Immediately after that treatment the heated nuclei showed an enlargement and the cooled nuclei a reduction in their visible size. The nuclei of these cells were afterwards measured at intervals of four hours. They showed the same diurnal changes as the ones in untreated cells, but shortly before cell death the cooled nuclei became larger and the heated nuclei got smaller. In this state the cooled nucleoli showed a little enlargement and the heated nucleoli a small reduction in size. Cladophora fracta andZygnema sp. were cultivated for a few days under short-day conditions (9 hours of daylight). After that treatment the size of the nuclei was reduced parallel with a reduction in heat resistance of the algae cells. When subsequently cultured in normal length of daylight the original size of the nuclei was restored.Similar temperature and daylength dependent variations in size of the nuclei will probably be found in the natural habitat of the algae during the day and also during the year.

     

Induction of metamorphosis in the sea urchin Holopneustes purpurascens by a metabolite complex from the algal host Delisea pulchra

Most benthic invertebrates have complex life cycles with planktonic larvae that return to the substratum to settle and metamorphose into a benthic stage. Although naturally produced chemical cues have long been thought to be important for the settlement or metamorphosis of invertebrate larvae, few ecologically relevant chemical cues have been clearly identified. The marine echinoid Holopneustes purpurascens has a complex life cycle, with a planktonic, nonfeeding dispersive larva that metamorphoses into a benthic stage that lives in the canopy of subtidal benthic algae such as the red alga Delisea pulchra and the kelp Ecklonia radiata. Recently recruited juveniles are found primarily on D. pulchra, and we hypothesized that this was in response to a chemical cue produced by this alga. Competent larvae metamorphosed in the presence of D. pulchra, or seawater surrounding this alga, but not in response to the presence of E. radiata or its extracts. A cue for metamorphosis was isolated and characterized from D. pulchra and found to be a water-soluble complex of the sugar floridoside and isethionic acid in a 1:1 molar ratio. The floridoside-isethionic acid complex also triggered settlement in H. purpurascens; however, this response was less specific than metamorphosis and was reversible. Larvae of H. purpurascens also metamorphosed in the presence of several other species of red, but not brown or green, algae from their habitat. Floridoside is found only in red algae, suggesting that the floridoside-isethionic acid complex may be acting as a cue for metamorphosis in other red algae as well as in D. pulchra.     

两种丝状绿藻对水体中低浓度苯酚的去除作用研究

研究了两种丝状绿藻,脆弱刚毛藻(Cladophora fracta)和长形水绵(Spirogyra longata)对水体中低浓度苯酚(≤6mg·mL-1)的去除作用。结果表明,在不考虑交互作用下,脆弱刚毛藻和长形水绵对苯酚的去除率分别为86%和75.63%,脆弱刚毛藻去除苯酚试验中,温度是主要影响因素,长形水绵去除苯酚试验中,处理时间是主要影响因素;在考虑交互作用下,脆弱刚毛藻和长形水绵对苯酚的去除率分别为88.98%和75.63%,脆弱刚毛藻去除苯酚试验中,温度是主要影响因素,长形水绵去除苯酚试验中,处理时间是主要影响因素;脆弱刚毛藻去除苯酚实验中各因素最优水平组合为温度18℃,处理时间2h,藻重0.5g,长形水绵去除苯酚试验中中各因素最优水平组合为温度8℃,处理时间1h,藻重0.5g。     

Natural inducers for coral larval metamorphosis

 Coral gametes from Acropora millepora (Ehrenberg, 1834) and from multi-species spawning slicks provided larvae for use in metamorphosis assays with a selection of naturally occurring inducer chemicals. Four species of crustose coralline algae, one non-coralline crustose alga and two branching coralline algae induced larval metamorphosis. However, one additional species of branching coralline algae did not produce a larval response. Metamorphosis was also observed when larvae were exposed to skeleton from the massive coral Goniastrea retiformis (Lamarck, 1816) and to calcified reef rubble, demonstrating metamorphosis is possible in the absence of encrusting algae. Chemical extracts from these algae and the coral skeleton, obtained using either decalcification or simple methanol extraction procedures, also contained active inducers. These results extend the number of crustose algal species known to induce coral metamorphosis, suggest that some inducers may not necessarily be strongly associated with the calcified algal cell walls, and indicate that inducer sources in reef habitats may be more diverse than previously reported. Accepted: 21 May 1999     

Occurrence of steryl glycosides and acylated steryl glycosides in some marine algae

There is some controversy concerning the presence of steryl glycosides and acylated steryl glycosides in eucaryotic algae. These two classes of sterol compounds were investigated in species belonging to the three major groups of eucaryotic algae: green algae (Ulva gigantea, Cladophora rupestris), brown algae (Fucus vesiculosus, Ascophyllum nodosum), and red algae (Rhodymenia palmata, Porphyridium sp.). All these algae contain both steryl glycosides and acylated steryl glycosides. The sterol components of these compounds vary according to the alga but they are always the same as the free sterols of the alga in question. The most common sugar moiety is glucose. In the acylated steryl glycosides, the fatty acid is mainly palmitic acid. The percentage of these compounds (as a percentage of the total sterol content) is often low.     

Genetic and environmental variation in performance of a marine isopod: effects of eutrophication

Environmental variation in food resources modifies performance of herbivores, in addition to genetic variation and maternal effects. In marine benthic habitats, eutrophication may modify herbivores diets by changing host species composition or nutritional quality of algae for herbivores. We studied experimentally the effects of diet breadth and nutrient availability for the host algae on fitness components of the herbivorous isopod Idotea baltica. We fed the adult isopods with the brown algae Fucus vesiculosus and Pilayella littoralis and juveniles with the green alga Cladophora glomerata. By using half-sib families, we were able to separate the genetic, environmental and maternal effects on intermolt duration and size of the juveniles. The mothers confined to the diet consisting of both Fucus and Pilayella grew better and produced larger egg mass than those having consumed Fucus alone. Nutrient enhancement of algae did not influence the performance of the adult herbivores. However, the juveniles achieved twice the weight as well as shorter intermolt duration when consuming nutrient-treated C. glomerata. Mothers nutrition, either nutrient enrichment of her food algae or diet breadth, did not affect juvenile survival or growth as such, but we found evidence that the broader diet consumed by the mother mediated offspring performance by further accelerating growth rate of the offspring that fed on nutrient-treated alga. Intermolt duration was a highly heritable trait, but size showed very low heritability. Instead, maternal effects on size were substantial, suggesting that differences among mothers in their egg-provisioning ability strongly affect weight gain of their offspring. A high amount of additive genetic variance in intermolt duration implies potential for quick evolutionary responses in the growth schedule in the face of changes in the selective environment. We conclude that eutrophication, in addition to improving growth and reproduction of I. baltica by enhancing food quality and by providing opportunity for broader, more profitable diets, may act as a selective agent on life-history traits. Eutrophication of coastal waters is thus likely to reflect in herbivore density, population dynamics and eventually, grazing pressure of littoral macroalgae.     

Cyanidium caldarium as a bridge alga between Cyanophyceae and Rhodophyceae: Evidence from immunodiffusion studies

The primer-independent phosphorylase isozyme, a₂, of Cyanidiumcaldarium was used for immunization of rabbits. The immune serumwas tested against pure a₂ isozymes from blue-green, red, andgreen algae. Double immunodiffusion in agar indicated that therewas structural similarity in the isozyme from Cyanidium caldarium,the blue-green algae, Oscillaloria princeps, Pleclonema nostocorumand the red alga, Rhodymenia pertusa. Complete fusion of theprecipitin lines was obtained with these algae. However, onlypartial fusion was observed with the a₂ isozymes from Chlorophyceaesuch as Chlorella pyrenoidosa and Spirogyra setiformis. Spurformation on the precipitin lines occurred when the isozymesfrom these algae were tested against the immuneserum. The results were interpreted as indicative of the possible transitionstatus of Cyanidium caldarium between prokaryotic blue-greenalgae and eukaryotic red algae. It would appear that the Chlorophyceaeevolved along different lines from Cyanophyceae than did theRhodophyceae. (Received November 25, 1975; )     

Effects of temperature on the production of hydrogen peroxide and volatile halocarbons by brackish-water algae

Marine algae produce volatile halocarbons, which have an ozone-depleting potential. The formation of these compounds is thought to be related to oxidative stress, involving H2O2 and algal peroxidases. In our study we found strong correlations between the releases of H2O2 and brominated and some iodinated compounds to the seawater medium, but no such correlation was found for CHCl3, suggesting the involvement of other formation mechanisms as well. Little is known about the effects of environmental factors on the production of volatile halocarbons by algae and in the present study we focused on the influence of temperature. Algae were sampled in an area of the brackish Baltic Sea that receives thermal discharge, allowing us to collect specimens of the same species that were adapted to different field temperature regimes. We exposed six algal species (the diatom Pleurosira laevis, the brown alga Fucus vesiculosus and four filamentous green algae, Cladophora glomerata, Enteromorpha ahlneriana, E. flexuosa and E. intestinalis) to temperature changes of 0-11 degrees C under high irradiation to invoke oxidative stress. The production rates, as well as the quantitative composition of 16 volatile halocarbons, were strongly species-dependent and different types of responses to temperature were recorded. However, no response patterns to temperature change were found that were consistent for all species or for all halocarbons. We conclude that the production of certain halocarbons may increase with temperature in certain algal species, but that the amount and composition of the volatile halocarbons released by algal communities are probably more affected by temperature-associated species shifts. These results may have implications for climatic change scenarios.     

山西省辛安泉泉域三种泉溪大型藻类植物附生藻类的研究

对三种泉溪大型藻类(脆弱刚毛藻, 弧形串珠藻和普生轮藻)藻体上附生藻类的种类、分布及环境因子与寄主本身对其的影响进行了研究。2004 年7 月至2005 年4 月在山西省辛安泉泉域采集三种大型藻类植物(每个季节采集一次)。研究结果表明, 三种大型藻类藻体上的附生藻类种类数不同, 普生轮藻上的附生藻类有49 种, 脆弱刚毛藻上37 种, 弧形串珠藻上6 种, 其中硅藻门种类数最多。这说明寄主本身结构的复杂程度在一定意义上会影响附生藻类的种类数及多样性。就季节变化而言, 三种大型藻类藻体上的附生藻类也表现出了明显的季节性,大致趋势为: 春季>秋季>夏季>冬季, 同时, 灰关联分析结果也表明, 环境因子在一定程度上对附生藻类也有影响, 最关键的影响因子是流速、水深和电导。这说明影响大型藻类植物藻体上附生藻类的影响因素是多方面的, 不仅有寄主本身, 同时流速、水深和电导这三种环境因子也起到了很关键的作用。       

Complexity and idiosyncrasy in the responses of algae to disturbance in mono- and multi-species assemblages

There is considerable debate about whether stability (e.g. inertia) of an assemblage, or of individuals in an assemblage, is positively associated with the number of species or whether there are idiosyncratic effects of particular species. We assessed the general model that the loss of an individual alga, caused by trampling, is greater in monospecific than in multi-species stands but that the responses of algae are idiosyncratic, depending on the morphology of the species. The experiment was done on conspicuous and dominant algae with different morphology on temperate Australian rocky shores: the fucalean algae Hormosira banksii and Sargassum sp. and the coralline alga Corallina officinalis. We assessed the relative and interactive effects of the extent of trampling (number of paths) and the localised intensity of trampling (number of travels per path) on the three algae. The number of paths trampled (the extent of disturbance) had more impact on each alga than the number of times paths were travelled (the intensity of disturbance). As predicted, H. banksii was most susceptible to trampling at each level than were the coarser algae Sargassum sp. and C. officinalis. There was a consistent trend for each alga to be more inert to trampling when in the presence of the other two species than when in monospecific stands, but this was only statistically significant (P < 0.05) for the softer alga H. banksii. The responses of H. banksii and Sargassum sp. to disturbance seemed, in many cases, to be due to the presence of C. officinalis rather than to "diversity" per se. The relationship between the number of species and stability is complex in intertidal habitats, depending on the species and the combinations of species with which it grows.     

Herbivory in an acid stream

• 1 Spatial and temporal variation in the distribution and feeding of non‐predatory macroinvertebrates was investigated in a first‐order, acid stream in the Ashdown Forest, southern England.
• 2 Stonefly (Nemouridae) and chironomid (Orthocladiinae) larvae were abundant on the upper surfaces of mineral substrata of three sizes (small stones, large stones, bedrock). The density of larvae in each taxonomic group did not vary among substrata of different sizes, although strong seasonal variation existed.
• 3 Nemourids and chironomids (H. marcidus) collected from the upper surfaces of substrata exhibited generalist feeding habits, consuming algae (diatoms, coccoid and filamentous green algae), detritus (biofilm matrix material and fine particulate organic matter (FPOM)) and inorganic debris.
• 4 There was spatial variation in the gut contents of nemourids. The proportion of algae in the guts of larvae often increased with the size of the substratum from which they were collected. Strong temporal variation in the composition of the diet also existed. Nemourids ingested a large quantity of attached algae and biofilm matrix from the biofilm in spring and winter, but consumed loose FPOM and associated microflora in summer and autumn.
• 5 We conclude that, in this acid stream, the trophic linkage between algae and grazers is maintained by ‘detritivorous’ stonefly and chironomid species. The relationship between the feeding habits of these larvae and other life‐history attributes, such as mouthpart morphology and mobility, is discussed.

     

Effects of food quality on growth and biochemical composition of a calanoid copepod,Argyrodiaptomus furcatus,and its importance as a natural food source for larvae of two tropical fishes

Growth, reproduction and biochemical composition were analyzed for the copepod Argyrodiaptomus furcatus fed on the alga Ankistrodesmus gracilis grown in different media. The ingestion of this copepod by larvae of two species of tropical fishes was also evaluated. The mean peak density of the copepod population was 1369 individuals l^–1 for all four diets used, and the highest was 1387 individuals l^–1 on diet ARV (algae + ration + vitamins). A small copepod, A. furcatus tends to have a short life span. The smallest females did not attain maturity in the shortest time on all diets used. Food quality may play a major role in the dynamics of the biochemical composition of this copepod. Argyrodiaptomus furcatus was a more important food item for larvae of tambaqui (Colossoma macropomum) than of pacu (Piaractus mesopotamicus). However, it made up a large part of the gut contents of larvae of both species.     

Larval settlement of the common Australian sea urchin Heliocidaris erythrogramma in response to bacteria from the surface of coralline algae

Bacterial biofilms are increasingly seen as important for the successful settlement of marine invertebrate larvae. Here we tested the effects of biofilms on settlement of the sea urchin Heliocidaris erythrogramma. Larvae settled on many surfaces including various algal species, rocks, sand and shells. Settlement was reduced by autoclaving rocks and algae, and by treatment of algae with antibiotics. These results, and molecular and culture-based analyses, suggested that the bacterial community on plants was important for settlement. To test this, approximately 250 strains of bacteria were isolated from coralline algae, and larvae were exposed to single-strain biofilms. Many induced rates of settlement comparable to coralline algae. The genus Pseudoalteromonas dominated these highly inductive strains, with representatives from Vibrio, Shewanella, Photobacterium and Pseudomonas also responsible for a high settlement response. The settlement response to different bacteria was species specific, as low inducers were also dominated by species in the genera Pseudoalteromonas and Vibrio. We also, for the first time, assessed settlement of larvae in response to characterised, monospecific biofilms in the field. Larvae metamorphosed in higher numbers on an inducing biofilm, Pseudoalteromonas luteoviolacea, than on either a low-inducing biofilm, Pseudoalteromonas rubra, or an unfilmed control. We conclude that the bacterial community on the surface of coralline algae is important as a settlement cue for H. erythrogramma larvae. This study is also an example of the emerging integration of molecular microbiology and more traditional marine eukaryote ecology.     

Green urchin as a significant source of fecal particulate organic matter within nearshore benthic ecosystems

The role of green sea urchin Strongylocentrotus droebachiensis as a source of fecal particulate organic matter (POM) for the benthic nearshore ecosystems has been studied over a 3.5-month period. Three macroalgae were tested as food sources: Alaria esculenta, Laminaria longicruris and Ulvaria obscura. Urchins were fed ad libitum with either a single alga species or a mixture of all three algae. Consumption and defecation rates were determined as well as the feces/alga ratio in term of biomass and biochemical composition. Consumption rate increased exponentially with urchin size and also varied with alga species. In the single alga trial, consumption rate was higher for both brown algae (Laminaria and Alaria) compared to Ulvaria. Urchins feeding on the mixture of algae maintained their total ingestion rate (sum of the three algae) at the same level to those feeding on a single alga diet. The mixed algae trial showed that urchins clearly preferred Laminaria (72% of total ingestion) over Alaria (22%) and Ulvaria (6%). The defecation rate was tightly correlated with the food consumption rate and thus increased with urchin size. On average, 75% of the ingested algal biomass was released as fecal POM. The percentage of food defecated changed with alga species, with the highest value for Alaria (81%) and the lowest for Laminaria (67%). The percentage of food defecated by urchins feeding on the mixture of algae was generally comparable to those feeding on single alga diet. Biochemical composition (in soluble carbohydrates, proteins and lipids) of urchin fecal POM reflected that of the algae content. From 40% to 80% of macronutrients in algal food persisted in fecal matter. This proportion varied with the alga species and macronutrient considered. This study shows that the green sea urchin plays a significant role in the production of POM within nearshore benthic ecosystems, and it is a potentially nutritious food source for detritivores.