WIOMSA is a membership Association with the following membership categories:

• Student members- nationals of any of the member states of the Region and registered as student at educational institutions recognized as such by WIOMSA. Student membership is free.
• Individual members-marine scientists and other professionals who are nationals of the countries of the Region involved in marine scientific and related activities.
• Associate members- marine scientists and other professionals from outside the Region involved in activities contributing to the objectives of the Association.
• Institutional membership: Available to any institution, company, agency, corporation and organization involved in activities furthering the aims of WIOMSA and whose objectives are not in conflict with the aims of the Association.
• Corporate membership: open to any private sector or business involved in activities furthering the aims of WIOMSA and whose objectives are not in conflict with the aims of the Association.
• Fellow membership: awarded by WIOMSA to scientists and others in recognition of outstanding work or significant contribution to marine science research in the region.
• Honorary membership: conferred by WIOMSA upon individuals who have rendered a notable service to marine science development in the Region

Rights and Obligations of Members
Each member of the Association shall have rights and perform such duties as may be prescribed by the General Assembly of the Association, including but not limited to the following:

1. Participate fully in the activities of the Association.
2. Avail him/herself of the facilities of the Association.
3. Undertake such obligations and duties as may be assigned by the General Assembly or Board of Trustees
4. Abide by the terms of this Constitution which shall be the basic guide for the operation of the Association.
5. Members of all categories shall enjoy the privileges of the Association.
6. All Members are entitled to vote (one person one vote).

Termination of Membership:

1. A person shall cease to be a member of the Association upon his/her death.
2. A person shall cease to be a member upon his/her own decision, expressed in writing to the Executive Secretary to withdraw membership.
3. Any person who without any reasonable cause ceases to continue to participate in the activities of the Association or ceases to pay membership subscription fees shall cease to be a member.
4. A person shall cease to be a member of the Association because of misconduct detrimental to the Association.
5. The resignation of any Member shall be communicated to the Assembly as soon as is practicable.