The increasing demand for raw materials along with declining discoveries of new prospects and exhaustion of terrestrial natural resources resulted in a growing interest in offshore exploration and extraction. Offshore magnetite resources play a big role in supplying much needed iron in the steel industry whilst marine aggregates satisfy the growing need for reclamation materials. With the increase in activity in the offshores of the Philippines, concerns regarding the associated potential environmental impacts and how authorities will regulate this emerging industry sustainably have arisen. Formulation of preliminary recommendations and guidelines which will serve as the basis of minimum baseline and monitoring data requirements needed for environmental management is pivotal in the effective impact mitigation and the overall preservation of the marine environment.
Guidelines were divided into categories, namely: pre-extraction; operations monitoring; post- extraction; and mitigating measures. Pre-extraction guidelines involve the gathering of baseline data requirements for 1) seabed sediment characterization (grain size and distribution, composition, density), 2) water quality assessment (initial pH, turbidity, dissolved oxygen, nutrient levels), 3) physical oceanographic setting (current speed/direction, sedimentation rates), 4) ambient noise, 5) coastal geomorphology (including current erosion and accretion rates), 6) seabed topography and 7) characterization of biological communities (pelagic, midwater and benthic). Data will also be used to construct models (e.g., hydrodynamic models) that aim to predict and quantify the effect of the proposed operations on the coastal environment and marine ecosystem. Monitoring of operations is then required to assess the actual impacts, test and validate the predictions made and ensure compliance with permit requirements. Upon completion of the project, post-extraction monitoring must be carried out in accordance with the post-extraction monitoring plan. Mitigating measures concerning waste management, hazardous materials handling, discharge of non-valuable minerals, turbidity mitigating technology (silt curtains, ‘green valve’, etc) were also outlined. Other considerations such as communication with other seabed users (e.g fisherfolk), subsea cables, archaeological discoveries and reporting concerns were also addressed.
The formulation of these guidelines is part of the effort for the build-up of environmental best practices concerning offshore exploration and extraction. The efficacy and applicability of these guidelines is to be assessed by implementing it on forthcoming offshore applications and currently operating offshore mines.
I. Introduction
The rapid acceleration of industrialization globally has led to a rise in consumption of raw materials thereby increasing the demand for mineral resources (Vidal et al., 2017). Driven by this demand and the declining grades and tonnages of terrestrial natural resources, extraction of mineral resources from the seabed, also referred to as offshore mining, is gaining traction considering the recent advancements in technology (Kaikkonen et al., 2018). Within the Philippine Exclusive Economic Zone (EEZ), of particular interest is the extraction of magnetite sand which is a major source of iron for the steel-making industry. Aside from magnetite sand, marine sand is also extracted for land reclamation projects, examples of which are the Pasay 265 project which involves the construction of two (2) islands, 210 and 55 hectares respectively (Technotrix Consultancy Services Inc., 2018); and the New Manila International Airport (NMIA) construction to be built on 1700 hectares of reclaimed land off the coast of Manila Bay at Bulakan, Bulacan (Macdonald, 2021).
Compared to its terrestrial counterpart, the knowledge regarding marine mineral resources is limited (Kaikkonen et al., 2018) and due to the nature and scale of activities, potential adverse impacts on the environment and surrounding ecosystem will be widespread and likely to be irreversible (Miller et al., 2018). Mitigation of these potential adverse impacts starts with a robust understanding of the environment in which the site is located. Baseline characterization provides a detailed account of the environmental conditions against which impacts will be measured and assessed. Regulatory bodies must identify and establish minimum baseline and monitoring data requirements to facilitate effective decision-making and policy responses for the protection and preservation of the marine environment.
In this paper, we develop a set of comprehensive guidelines by collating best environmental practices and reviewing peer-reviewed related literature on recent developments within this industry and localizing it as applicable to the Philippine setting. During a recent workshop with experts from DENR-BMB, UP-MSI and UP- NIGS and other stakeholders, the guidelines were categorized into four (4) categories, namely: 1) Pre-extraction (Baseline Characterization); 2) Operations Monitoring; 3) Mitigating Measures and 4) Post-extraction monitoring.