Prof. Gavin Maneveldt

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https://hdl.handle.net/10566/1536

Position:	Professor
Department:	Biodiversity and Conservation Biology Programme
Faculty:	Faculty of Natural Science
Qualifications:	BSc, BSc(Hons), MSc, PhD (UWC)
	FGASA Honorary SKS (Marine Guiding)
	Research publications in this repository
ORICD iD	0000-0002-5656-5348
More about me:	here and here
Tel:	021 959 2342/2301	Fax:	021 959 2312
Email:	gmaneveldt@uwc.ac.za

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Now showing 1 - 20 of 42

South African seaweed aquaculture: A sustainable development example for other African coastal countries
(Academic Journals, 2013) Amosu, Albert O.; Robertson-Andersson, Deborah; Maneveldt, Gavin; Anderson, Robert J.; Bolton, John J.
The green seaweed Ulva is one of South Africa's most important aquaculture products, constituting an important feed source particularly for abalone (Haliotis midae L.), and utilized as a bioremediation tool and other benefits such as biomass for biofuel production and for integrated aquaculture. Besides Ulva spp, Gracilaria spp. are also cultivated. Wild seaweed harvest in South Africa totals 7,602 mt, compared to 2,015 mt of cultivated Ulva. To mitigate for the reliance on wild harvesting, the South African seaweed aquaculture industry has grown rapidly over the past few decades. On-land integrated culture units, with paddle-wheel raceways, are now widely viewed as the preferred method of production for the industry. The success of seaweed aquaculture in South Africa is due to a number of natural and human (industrial) factors. The development of the seaweed aquaculture industry has paralleled the growth of the abalone industry, and has been successful largely because of bilateral technology transfer and innovation between commercial abalone farms and research institutions. In South Africa seaweeds have been used commercially as feedstock for phycocolloid production, for the production of abalone feed, and the production of Kelpak and Afrikelp, which are plant-growth stimulants used in the agricultural sector. Additionally, Ulva is being investigated for large-scale biogas production. The South African seaweed industry provides a template that could be used by other coastal African nations to further their undeveloped aquaculture potential.
The chromista
(Wiley Online, 2003) Maneveldt, Gavin; Keats, Derek
As a group, the chromists show a diverse range of forms from tiny unicellular, flagellates to the large brown algae known as kelp. Molecular studies have confirmed the inclusion of certain organisms once considered Fungi, as well as some heterotrophic flagellates. Despite their diversity of form and feeding modes, a few unique characters group these organisms.
Chromista
(Wiley Online, 2011) Sym, Stuart D.; Maneveldt, Gavin
The concept of chromists, at its most expansive, includes the heterokonts (stramenopiles), alveolates, rhizarians, heliozoans, telonemians, haptophytes and cryptophytes. There is mounting evidence that this grouping is not valid. Even in the narrowest sense (the heterokonts), chromists include very diverse forms, exhibiting a great variety of trophic mechanisms. This great diversity in form and feeding make it difficult to identify any unifying features, but molecular phylogenetic studies have shown that this group of organisms is indeed monophyletic. The distribution of morphological characters over reconstructed trees allows for the identification of potential synapomorphic characters that have been secondarily lost or modified across the group. These include a combination of mitochondria with tubular cristae; the biflagellate heterokont condition; and, if photosynthetic, then with chlorophyll c, girdle lamellae and four membranes around the chloroplast, the outer continuous with the nuclear envelope. Heterotrophy appears to be ancestral but is also occasionally a derived state from autotrophic forms.
How to write a popular article
(SANCOR, 2008) Maneveldt, Gavin; Moore, R.; Day, J.; Reid, J.
This newsletter has criteria for the development of a popular article.
Life at the margins of the continents: an examination of the intertidal marine life of the south Western Cape
(Field Guides Association of Southern Africa, 2010) Maneveldt, Gavin
Imagine surviving in an environment that is neither truly marine nor truly terrestrial. That area just beyond the low-water mark of neap tides along the seashore is an example of just such an environment. The organisms living here have to cope with the combined extremes of both land and sea environments: salt spray, immersion in salt water, emersion in air, drenching by heavy rainfall, heating by the sun, freezing winter temperatures, unstable substrates (such as sand, gravel or boulders), and exposure to strong winds. Just how do they cope? Animals generally find it easier coping in this harsh environment because among other ways, they can simply get up and move when the going gets too tough. Plants (both terrestrial and marine) on the other hand, have to either tolerate, or succumb to it. The following is an account of some of the astonishing ways in which both plants and animals from a typical southwestern Cape shore have evolved to adapt and cope in the harsh environment of the intertidal zone.
Structure of rhodolith beds from 4 to 55 meters deep along the southern coast of Espírito Santo State, Brazil
(Universidad Autónoma de Baja California, 2007) Amado-Filho, Gilberto M.; Maneveldt, Gavin; Manso, R.C.C.; Marins-Rosa, B.V.; Pacheco, M.R.; Guimarães, S.M.P.B.
Rhodoliths are one of the most extensive benthic communities of the Brazilian continental shelf, but their structure is poorly known. The richest marine flora of Brazil’s coastal zone is found in Espírito Santo State and its diversity has been partly associated with the presence of extensive areas of rhodoliths, extending from the intertidal zone to 120 m across the continental shelf. One species of kelp, Laminaria abyssalis, is endemic to this area and occurs between 45 and 120 m depth. Our objective was to determine the density and physical dimensions of the superficial rhodoliths between 4 and 55 m depth in the southern region of Espírito Santo State. The study area was 3 to 45 km offshore. Samples were obtained in 2004 and 2005 by Scuba diving in three depth zones: 4–18 m, 25–30 m and 50–55 m. Transect lines and video images were used to determine rhodolith density. The diameter and sphericity of at least 60 individuals from each zone were measured. Rhodolith size increased and density decreased from the shallow to the deeper zones. Spheroidal was the typical shape throughout the depth zones. Five rhodolith-forming genera were identified: Lithothamnion, Lithophyllum, Hydrolithon, Neogoniolithon and Sporolithon. Epibenthic biomass and species richness over the rhodolith bed in the shallow zone was lowest in winter, likely the result of disturbance caused by typical winter storms. Changes in light and temperature are probably the most important factors in the changes observed in the rhodolith beds from the deepest zones.
Of dead man's fingers, cord weed and hanging wrack: common brown seaweeds of the Cape Peninsula
(Botanical Society of South Africa, 2000) Maneveldt, Gavin; Frans, Rene
In this, the second in the series on common intertidal seaweeds of the Cape Peninsula, we look at the brown seaweeds common to our rocky shores, with the exception of kelp, which will be covered in the next issue of Veld & Flora. Unlike the green seaweeds mentioned in the previous issue, these brown seaweeds are generally slower growing and are less tolerant of salinity and temperature extremes and thus more prone to desiccation stress. They therefore tend to occur lower down on the shore than the green seaweeds.
Seaweed diversity associated with a Brazilian tropical rhodolith bed
(Universidad Autónoma de Baja California, 2010) Amado-Filho, Gilberto M.; Maneveldt, Gavin; Pereira-Filho, G.H.; Manso, R.C.C.; Bahia, Ricardo
This study describes the predominantly tropical, subtidal seaweed populations growing on rhodoliths between 4 and 18 m depth in the southern part of Espírito Santo State (Brazil). Qualitative and quantitative sampling revealed species-rich algal communities, comprising 167 species. Three species of rhodophytes represent new records for the Brazilian marine flora (Lithothamnion muelleri, Scinaia aborealis, and Mesophyllum engelhartii). Marked seasonal differences in fleshy algal species composition and abundance were related to seasonal instabilities caused by winter-storm disturbance over the rhodolith beds. In relation to depth, rhodolith density appears to be an important factor for the variation in the abundance of fleshy algae. The rhodolith community is composed of at least seven nongeniculate crustose coralline algal species. Rhodolith beds in southern Espírito Santo State, in an area of 150 km2, provide an important habitat for epibenthic communities, supporting 25% of the known macroalgal species richness along the Brazilian coast.
Two new melobesioid algae (Corallinales, Rhodophyta), Synarthrophyton robbenense sp. nov. and S. munimentum sp. nov., in South Africa and Namibia
(International Phycological Society, 1997) Keats, Derek; Maneveldt, Gavin
Synarthrophyton robbenense sp. nov. and S. munimentum sp. nov., the fourth and fifth species in this apparently southern hemisphere genus, are described from southern Africa. Synarhrophyton robbenense occurs on rock and shells in the subtidal zone. Its thalli are minutely warty, with the surface covered by short, narrow protuberances that are fused into elongate, scrolled structures. The surface [scanning electron microscopy (SEM)] is of the Leptophytum type. Mature tetraibisporangial conceptacles have raised rims and sunken pore plates. The pore plates are composed of filaments made up of two or three cells plus an enlarged epithallial cell. The pore canal is lined by filaments with cells that do not differ in size or shape from those of the other filaments making up the pore plate. Cells of filaments within the tetrasporangial and bisporangial conceptacle rim are narrower and more elongate than cells of the pore plate and surrounding vegetative filaments. Tetralbisporangial pores are surrounded by five to eight rosette cells that tilt somewhat toward the pore in surface SEM view. Tetraibisporangial conceptacles do not become buried in the thallus, but are shed on senescence, often leaving shallow craters on the surface. Synarthrophylon munimenlum occurs on rocks and shells in low-shore tide pools, and on rock, shells, and kelp holdfasts in the subtidal zone. Thalli are usually smooth, occasionally warty, but never show protuberances that are fused into scrol l-like structures. The thallus surface (SEM) is made up of Leptophytum-type epithallial cells. Tetral bisporangial conceptacle roofs are volcano-shaped with a raised peripheral rim and sunken pore plate. The pore plates are composed of filaments made up of five to seven cells plus an epithallial cell. The rosette cells that surround the tetral bisporangial pore are distinct from surrounding roof cells (SEM, surface view) in being narrower and sunken below the level of the surrounding pore plate. The pore canal is lined by filaments with cells that do not differ in size or shape from those of the other filaments making up the pore plate. Cells of filaments within the tetrasporangial and bisporangial conceptacle rim are more or less similar in size and shape to cells of the pore plate and surrounding vegetative filaments.
Three species of Mastophora (Rhodophyta: Corallinales, Corallinaceae) in the tropical Indo-Pacific Ocean: M. rosea (C. Agardh) Setchell, M. pacifica (Heydrich) Foslie, and M. multistrata sp. nov
(International Phycological Society, 2009) Keats, Derek; Maneveldt, Gavin; Baba, Masasuke; Chamberlain, Yvonne; Lewis, Jane E.
Three species of Mastophora (Corallinaceae, Corallinales, Rhodophyta) were found in extensive studies of non-geniculate coralline algae in various areas of the tropical Indo-Pacific, including French Polynesia, Fiji, Ryukyu Islands (Japan) and Taiwan. Two species are delicate and leafy, but are distinguishable on morphological grounds. Mastophora rosea plants are taeniform, dichotomously branched, weakly calcified, and have rolled margins. Their thalli show very little secondary growth, with only occasional small round patches at the surface. Tetrasporangial and carposporangial conceptacles are very high (330-640 m), and dome-shaped to almost spherical. Mastophora rosea plants collected during this study stand out in the water because of their bluish-purple colour. Mastophora pacifica has more strongly calcified thalli that are irregularly branched, with abundant secondary growth and the development of loosely attached, crispy layers. Tetrasporangial and carposporangial conceptacles are conical (280-550 m high). Thallus colour in M. pacifica varies substantially depending on where it is growing, ranging from violet brown to dark red to greyish ruby, but are mostly pale-pink to reddish-purple in their submerged living state. Mastophora multistrata sp. nov. plants are hard and robust. Their thalli are made up of tightly packed layers that are only evident in section. Tetrasporangial conceptacles are generally low (315-490 m high) and dome shaped. In their living state, M. multistrata plants are usually deep-purple plum coloured.
Abalone farming in South Africa: an overview with perspectives on kelp resources, abalone feed, potential for on-farm seaweed production and socio-economic importance
(Elsevier, 2006) Troella, M. D.; Robertson-Andersson, Deborah; Anderson, Robert J.; Bolton, John J.; Maneveldt, Gavin; Halling, C.; Probyn, T.
The South African abalone cultivation industry has developed rapidly and is now the largest producer outside Asia. With a rapid decline in wild abalone fisheries, farming now dominates the abalone export market in South Africa. Kelp (Ecklonia maxima) constitutes the major feed for farmed abalone in South Africa, but this resource is now approaching limits of sustainable harvesting in kelp Concession Areas where abalone farms are concentrated. This paper gives an overview of the development of the South African abalone industry and analyses how abalone farming, natural kelp beds and seaweed harvesting are interlinked. It discusses options and constraints for expanding the abalone industry, focussing especially on abalone feed development to meet this growing demand. Kelp will continue to play an important role as feed and kelp areas previously not utilised may become cost-effective to harvest. There are many benefits from on-farm seaweed production and it will probably be a part of future expansion of the abalone industry. Abalone waste discharges are not at present regarded as a major concern and farming brings important employment opportunities to lower income groups in remote coastal communities and has positive spill-over effects on the seaweed industry and abalone processing industry.
Is your garden green? How to be kind to your garden
(Botanical Society of South Africa, 2008) Maneveldt, Gavin
Years ago, there was plenty of open, natural veld surrounding our towns and it was rich in wildlife. As towns expanded the natural veld and wildlife shrank into patches between towns, factories and farm land. With this reduction in natural areas, suburban gardens now form an important place where wild animals can live and indigenous plants can flourish. There are many things that one can do to be an ‘environmentally friendly’ gardener.
Of dinner plate, cochlear and pacman corallines: seven common intertidal encrusting red seaweeds of the Cape Peninsula
(Botanical Society of South Africa, 2001) Maneveldt, Gavin; Frans, Rene
In the fifth and final part of this series of articles on common intertidal seaweeds of the Cape Peninsula, we look at encrusting coralline algae. These encrusting coralline and red seaweeds are widespread in shallow waters in all the world’s oceans, where they often cover close to 100% of rocky substrates. Nowhere are they more important than in the ecology of coral reefs. Not only do encrusting coralline algae help cement the reef together, but they make up a considerable portion of the mass of the reef itself and are important primary products and food for certain herbivores.
Of purple laver, tongue weed and hedgehog seaweed: common red seaweeds of the Cape Peninsula
(Botanical Society of South Africa, 2001) Maneveldt, Gavin; Frans, Rene
The fourth part of our series on the common intertidal seaweeds of the Cape Peninsula looks at the red seaweeds, which form by far the largest group of seaweeds on the Peninsula and dominate the mid to lower intertidal area to a large extent. Like the brown seaweeds many of the reds are fleshy and bulky and generally occur lower down the shore because they are less tolerant of salinity and temperature extremes than some of the common green seaweeds.
Of sea bamboo, split fan kelp and bladder kelp: three common kelp species of the Cape Peninsula and West Coast
(Botanical Society of South Africa, 2001) Maneveldt, Gavin; Frans, Rene
The third part in our series on the common intertidal seaweeds of the Cape Peninsula looks at the kelps, the giant brown seaweeds that occur in the subtidal and intertidal gullies of the Cape Peninsula and the west coast. Like trees an ancient forest, kelp dominate the canopy of the subtidal zone in the cool, nutrient-rich waters of the South African west coast. Kelp is the largest and fastest growing of the seaweeds, growing as much as 13 mm in a day. Some of these seaweeds as the giant kelp (Macrocystis pyrifera) of central and southern California are known to grow to over 30 m in length.
Of sea lettuces and green sea intestines: common intertidal green seaweeds of the Cape Peninsula
(Botanical Society of South Africa, 2000) Maneveldt, Gavin; Frans, Rene
Most of us know seaweed as that slippery stuff growing on the rocks or lying strewn along the beach at low tide making the beach smell. But do we really know much about them? Although not entirely true, seaweeds (or marine algae) are generally considered to be plants because they use solar energy to produce carbohydrate food from carbon dioxide and water (photosynthesis). They are simpler than land plants as they have no roots or shoots. Seaweeds absorb nutrients directly from the seawater; and therefore have no need for roots or complex conductive tissue. Some large seaweeds do however have root-like structures called holdfasts and leaf-like fronds that act like shoots. The photosynthetic pigments they possess reflect certain colours of light, producing what appear to be green, brown and red seaweeds, and thus they are divided into three main groups: green brown and red. In this article we examine some of the green seaweeds that occur in the Cape Peninsula.
Abundance and species composition of non-geniculate coralline red algae epiphytic on the South African populations of the rocky shore seagrass Thalassodendron leptocaule M.C. Duarte, Bandeira & Romeiras
(Elsevier, 2013) Browne, Catherine M.; Maneveldt, Gavin; Bolton, John J.; Anderson, Robert J.
Seagrasses support a great diversity of epiphytic organisms and new research has shown that non-geniculate coralline red algae are important occupiers of space on the fronds of seagrasses. Except for a few scant records, there are no detailed published accounts of non-geniculate coralline algae epiphytic on seagrasses in South Africa. The seagrass Thalassodendron leptocaule (previously known as Thalassodendron ciliatum) is unique among southern African seagrasses in that it occurs on exposed rocky outcrops along the Mozambique and north eastern South African coast; most other seagrasses are restricted to sheltered bays and estuaries. Here we present descriptions of three species of non-geniculate coralline red algae which we have identified growing epiphytically on this seagrass in northern KwaZulu-Natal: Hydrolithon farinosum, Pneophyllum amplexifrons and Synarthrophyton patena. Two of the corallines (P. amplexifrons and S. patena) were restricted to the seagrass' stems while the third (H. farinosum) occurred only on the leaves. Of the three coralline epiphytes, P. amplexifrons contributed most to the biomass (average wet weight per plant 0.6±1.18 g); its wet weight, however, varied between habitats. Hydrolithon farinosum and other smaller turf algae amounted to no more than 0.1 g (wet weight) per leaf. Synarthrophyton patena was far more sparsely evident and contributed to less than 0.1 g (wet weight) per stem. Pneophyllum amplexifrons and H. farinosum appear to be pioneer epiphytes and form additional surfaces onto which other seaweed epiphytes attach and grow. Distribution of these epiphytes is explained by the longevity of the stems and leaves of the seagrass.
West Coast plants for a waterwise garden
(Botanical Society of South Africa, 2009) Maneveldt, Gavin
The new gardening mantra is 'grow indigenous'. Besides their aesthetic value, most indigenous plants are less costly to maintain, largely because they have long adapted to the local climate and thus to the local rainfall. For this reason, many indigenous plants, particularly those adapted to low rainfall environments, are more cost effective in their water consumption and many have subsequently been termed waterwise plants. But, why encourage waterwise gardens? First and foremost, it is important to mention that South Africa is a relatively dry country; most parts of the country receive less than 500 mm of rain per annum. With an ever-increasing population, the demand for this precious resource will grow. In response to both of these factors, we have already become accustomed to municipal water restrictions in the Western Cape during summer, as well as legislation pertaining to its conservative use. Despite this, the most alarming fact is that gardens, particularly those with large lawns, are still singled out as the main water-wasting culprits, often consuming up to 50% of all domestic water used in suburban areas. So, it makes perfect sense to convert to a waterwise garden - if you do not already have one - because they cut down on this waste.
Scale insects on ericas : an apparently natural, unnoticeable threat to local biodiversity
(Botanical Society of South Africa, 2008) Maneveldt, Gavin
Introduction: An excursion into the Limietberg Nature Reserve in the Bain's Kloof Mountains during the winter of 2006, one that I have undertaken regularly over the past ten years or so, had revealed a noticeably high number of dead and apparently dying individuals of Erica species.
Don't cut that 'grass'
(Botanical Society of South Africa, 2006) Marais, Karen; Maneveldt, Gavin
Introduction: Have you ever noticed the abundance of wildflowers on public open spaces during spring in Cape Town? I suppose some Capetonians would be aware of Rondebosch Common and the astonishing botanical diversity it contains, including many threatened species. However, it appears that very few people are aware of the many other public open spaces that may be just as precious and put on a spectacular spring flower show. But for how much longer?

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