DBMS Global Oceans works with a diverse range of stakeholders to mitigate the economic impact of depredation on fisheries and the conservation impact of by-catch on marine mammal and seabird populations. We draw upon the extensive experience of experts from diverse backgrounds and with proven track records to identify and characterise the nature of the problem, then develop, assess and implement strategies for mitigating marine mammal and seabird depredation and by-catch in today’s fisheries.




Competition for the same finite food resource in the marine environment attracts fishing operations, marine mammals and seabirds to the same location, thus increasing the chance of encounters, or operational interactions. Operational interactions can be divided into two categories. Depredation occurs when the natural predator interrupts human fishing operations while in search of food, resulting in reduced catch rates, or the landing of damaged fish. By-catch occurs when depredating individuals misjudge their movements around the fishing gear, or are naïve to the associated dangers, thus becoming caught themselves. Further detail about these definitions can be found under the Background page.


Dr Derek Hamer, DBMS Global Oceans Company Director, has a wealth of experience in this specialist field and also has broad and strong working relationships with key experts in several related research disciplines and in the fishery and fishery management communities. When a project is established between DBMS Global Oceans and a client, Dr Hamer commits his own capabilities and also engages appropriate experts as needed to ensure the best quality service is provided.

Collectively, their skills and experience relevant to the core work of DBMS Global Oceans includes:

  • Development and management of challenging vessel based and remote island research projects, sea trials and observer programs, short and long term, from the tropics to sub-Antarctic.
  • Broad stakeholder engagement to facilitate collaboration and inclusion, across industry associations, government and intergovernmental agencies, research communities and fishing gear manufacturers.
  • Characterisation of marine mammal and seabird operational interactions with industrial, commercial and artisanal fisheries.
  • Tracking of seals and seabirds, using satellite telemetry for geographic movement and time-depth recorders for dive behaviour.
  • Analysis of resulting movement data (e.g. GIS) for determining critical foraging areas and behaviours, and extent of overlap with fisheries.
  • Collection of by-catch data and ground based and aerial surveys of colonies and rookeries, to assess the impact on populations using population viability analyses (PVA).
  • Development and assessment of mitigation strategies, including gear modification and augmentation, changes in fisher behaviour using codes of practice, and time and area closures.
  • Design and manufacture of devices to augment fishing gear to mitigate by-catch and depredation, using the latest computer aided design (CAD) and selective laser sintering (SLS) tools for rapid prototype production.
  • Gear performance assessment through rigorously controlled and designed experiments and commercial sea trials.
  • Development and assessment of specific codes of practice to improve by-catch avoidance and release strategies, plus supporting literature and workshops for industry participants.
  • Efficacy assessment of spatial exclusion zones for conserving protected marine mammal and seabird populations.
  • Collection, collation and analyses of complex and multifactorial data, employing appropriate analyses via specialist software packages and custom script in R.
  • Production of high quality reports and publications for informing best practice for fishery and conservation management agencies, within Governments, Intergovernmental organisations (IGOs), non-government environment organisations (eNGOs), and fishing industry associations.
  • Provision of strategic and easy to interpret management advice to the consulting and/or applicable stakeholders, for the improvement for marine mammal conservation and/or improvement of fishery viability.