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Trends in seaweed resource use and aquaculture in South Africa and Namibia over the last 30 years

  • Mark D. Rothman

    Mark D. Rothman obtained his PhD in 2015 from the University of Cape Town, South Africa. He heads up the Seaweed Research Unit of the Department of Environment Forestry and Fisheries in South Africa. His research interests include seaweed resource management, seaweed aquaculture kelp ecology and systematics. He has published 15 peer-reviewed papers and has supervised several post-graduate students.

     EMAIL logo     , Robert J. Anderson

    Robert J. Anderson obtained a PhD (University of Cape Town) in 1982 and worked for the South African government department responsible for fisheries, as a seaweed biologist, until retirement in 2018. He collaborated on many national and international projects and has published widely on various aspects of phycology. His main interests include ecology and taxonomy of seaweeds. At present he remains an Honorary Associate Professor at UCT.

         , Lineekela Kandjengo

    Mr Lineekela Kandjengo is the Head for the Fisheries and Aquatic Sciences Department at the Sam Nujoma Campus, University of Namibia. He has taught in the Department of Fisheries and Aquatic Sciences, University of Namibia for over 15 years during which time he supervised more than twenty BSc Honours student projects and has more than ten peer-reviewed publications. His current research is primarily on the Namibian coastal biodiversity. He holds a BSc (Botany and Zoology) from the University of Namibia, a BSc Honours (Phycology and Biosystematics) and an MSc (Systematics and Biodiversity Science) from the University of Cape Town.

         and John J. Bolton

    Prof. John J. Bolton is Emeritus Professor of Biological Sciences and Senior Research Scholar at the University of Cape Town, South Africa. He is a marine plant biologist and research interests cover the biodiversity, biogeography, systematics, ecology and resource management of seaweeds, as well as the aquaculture of seaweeds and the integrated aquaculture of seaweeds and marine animals. He has over 150 peer-reviewed journal publications and has supervised 19 graduated PhD students.
Published/Copyright: July 22, 2020
Botanica Marina
From the journal Botanica Marina Volume 63 Issue 4

Abstract

The seaweed industry of temperate Southern Africa was last reviewed in 2003. Since then there have been considerable changes. There are three main uses of kelp (mostly Ecklonia maxima, with some Laminaria pallida) in South Africa. The collection of wash-up for drying and exporting for alginate extraction has drastically reduced to very small amounts in recent years. The boat harvest of fresh kelp for abalone feed in land-based farms has reached a plateau of between 4000 and 5000 t fresh per annum. The diver harvest of E. maxima for agricultural liquid plant growth enhancer shows a constant increase over several years, is still growing, and is currently over 3000 t fresh per annum. The small intertidal collection of Gelidium pristoides as export for agar production has maintained a small, sustainable production of around 100 t dry for many years. Former Gracilaria industries in sheltered bays in both South Africa and Namibia have collapsed, and there is currently no commercial collection. There was commercial raft aquaculture production of Gracilaria in Lüderitz Bay, Namibia for a number of years, but this is no longer practised. Currently, the only commercial seaweed use in Namibia is of L. pallida. Annually, ca. 150 t of fresh wash-up is collected, in Lüderitz, to be used as feed in land-based abalone aquaculture. There are a number of small start-up companies experimenting with seaweed products for cosmetics and nutritional products in both countries, some involving species of Ulva and Porphyra. The former species is a major aquaculture product, with around 2000 t fresh yr–1 being produced in integrated land-based systems with abalone.

Keywords: aquaculture; Namibia; seaweeds; South Africa; utilization
Corresponding author: Mark D. Rothman, Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch,7701, South Africa; and Department of Environment, Forestry and Fisheries, Private Bag X2, Vlaeberg, 8012, South Africa, E-mail:

Article note: This article is part of the special issue series of Botanica Marina: Seaweed resources of the world: a 2020 vision, which has started publication in Botanica Marina 2019, vol. 62, issue 3. The series is guest-edited by Alan T. Critchley, Anicia Hurtado, Leonel Pereira, Melania Cornish, Danilo Largo and Nicholas Paul.

Funding source: Department of Environment, Forestry and Fisheries, University of Cape Town

Funding source: National Research Foundation

About the authors

Mark D. Rothman

Mark D. Rothman obtained his PhD in 2015 from the University of Cape Town, South Africa. He heads up the Seaweed Research Unit of the Department of Environment Forestry and Fisheries in South Africa. His research interests include seaweed resource management, seaweed aquaculture kelp ecology and systematics. He has published 15 peer-reviewed papers and has supervised several post-graduate students.

Robert J. Anderson

Robert J. Anderson obtained a PhD (University of Cape Town) in 1982 and worked for the South African government department responsible for fisheries, as a seaweed biologist, until retirement in 2018. He collaborated on many national and international projects and has published widely on various aspects of phycology. His main interests include ecology and taxonomy of seaweeds. At present he remains an Honorary Associate Professor at UCT.

Lineekela Kandjengo

Mr Lineekela Kandjengo is the Head for the Fisheries and Aquatic Sciences Department at the Sam Nujoma Campus, University of Namibia. He has taught in the Department of Fisheries and Aquatic Sciences, University of Namibia for over 15 years during which time he supervised more than twenty BSc Honours student projects and has more than ten peer-reviewed publications. His current research is primarily on the Namibian coastal biodiversity. He holds a BSc (Botany and Zoology) from the University of Namibia, a BSc Honours (Phycology and Biosystematics) and an MSc (Systematics and Biodiversity Science) from the University of Cape Town.

John J. Bolton

Prof. John J. Bolton is Emeritus Professor of Biological Sciences and Senior Research Scholar at the University of Cape Town, South Africa. He is a marine plant biologist and research interests cover the biodiversity, biogeography, systematics, ecology and resource management of seaweeds, as well as the aquaculture of seaweeds and the integrated aquaculture of seaweeds and marine animals. He has over 150 peer-reviewed journal publications and has supervised 19 graduated PhD students.

Acknowledgements

We thank Chris Boothroyd and Derek Kemp for their assistance.

  1. Author contribution: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.

  2. Research funding: We are grateful for research funding from the Department of Environment, Forestry and Fisheries, University of Cape Town and the National Research Foundation (grant number 111719).

  3. Conflict of interest statement: The authors declare no conflicts of interest regarding this article.

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Received: 2019-10-10
Accepted: 2020-06-09
Published Online: 2020-07-22
Published in Print: 2020-08-27

© 2020 Walter de Gruyter GmbH, Berlin/Boston

Articles in the same Issue

  1. Frontmatter
  2. In this issue
  3. Editorial
  4. Seaweed resources of the world: a 2020 vision. Part 4
  5. Applications
  6. Seaweed utilisation in New Zealand
  7. Trends in seaweed resource use and aquaculture in South Africa and Namibia over the last 30 years
  8. Challenges for marine macroalgal biomass production in Indian coastal waters
  9. Technical challenges for offshore cultivation of kelp species: lessons learned and future directions
  10. Using macroalgae as biofuel: current opportunities and challenges
  11. Biogeography
  12. Seaweed resources of Tanzania: status, potential species, challenges and development potentials
  13. The seaweed resources of Peru
  14. Seaweed resources of Korea
https://doi.org/10.1515/bot-2019-0074
Keywords for this article
aquaculture; Namibia; seaweeds; South Africa; utilization

Articles in the same Issue

  1. Frontmatter
  2. In this issue
  3. Editorial
  4. Seaweed resources of the world: a 2020 vision. Part 4
  5. Applications
  6. Seaweed utilisation in New Zealand
  7. Trends in seaweed resource use and aquaculture in South Africa and Namibia over the last 30 years
  8. Challenges for marine macroalgal biomass production in Indian coastal waters
  9. Technical challenges for offshore cultivation of kelp species: lessons learned and future directions
  10. Using macroalgae as biofuel: current opportunities and challenges
  11. Biogeography
  12. Seaweed resources of Tanzania: status, potential species, challenges and development potentials
  13. The seaweed resources of Peru
  14. Seaweed resources of Korea
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